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Records |
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Author |
Xu, W.; Peeters, F.M.; Devreese, J.T. |
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Title |
Electrophonon resonances in a quasi-two-dimensional electron system |
Type |
A1 Journal article |
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Year |
1993 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
48 |
Issue |
3 |
Pages |
1562-1570 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
When the energy difference between two electric subbands in a quasi-two-dimensional electron system equals a LO-phonon energy, resonant scattering will occur. This leads to an enhancement of the scattering rate and, consequently, to a suppression of the conductivity. Changing the energy difference between the electric subbands (e.g., through a gate) leads to a series of electrophonon resonances in the conductivity. A detailed study is made of this effect for different confinement potentials. We found that the scattering processes where the emission of a phonon is involved are very important for the electrophonon resonance and that the size of the effect decreases with increasing temperature. |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
A1993LP05000024 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.736 |
Times cited |
45 |
Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ lucian @ c:irua:5747 |
Serial |
1022 |
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Author |
Peeters, F.M.; Vasilopoulos, P. |
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Title |
Quantum transport of a two-dimensional electron gas in a spatially modulated magnetic field |
Type |
A1 Journal article |
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Year |
1993 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
47 |
Issue |
3 |
Pages |
1466-1473 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Electrical transport properties of a two-dimensional electron gas axe studied in the presence of a perpendicular magnetic field B modulated weakly and periodically along one direction, B = (B + B0 cos Kx)z, with B0 much less than B, K = 2pi/a, and a being the period of the modulation. B0 is taken constant or proportional to B. The Landau levels broaden into bands and their width, proportional to the modulation strength B0, oscillates with B and gives rise to oscillations in the magnetoresistance at low B. These oscillations reflect the commensurability between the cyclotron diameter at the Fermi level and the period a and consequently hey are distinctly different from the Shubnikov-de Ha.as ones, at higher B, in period and temperature dependence. The bandwidth at the Fermi energy can be one order of magnitude larger, at low B, than that of the electric case for equal modulation strengths. The resulting magnetoresistance oscillations have a much higher amplitude than those of the electric case with which they are out of phase. Explicit asymptotic expressions are derived for the temperature dependence of the transport coefficients. The case when both electric and magnetic modulations are present is also considered. The position of the resulting oscillations depends on the ratio delta between the two modulation strengths. When the modulations are out of phase there is no shift in the position of the oscillations when delta varies and for a particular value of delta the oscillations are suppressed. |
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Place of Publication |
Lancaster, Pa |
Editor |
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Wos |
A1993KJ51800042 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.736 |
Times cited |
169 |
Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ lucian @ c:irua:5787 |
Serial |
2795 |
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Author |
Hai, G.Q.; Peeters, F.M.; Devreese, J.T. |
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Title |
Polaron-cyclotron-resonance spectrum resulting from interface- and slab-phonon modes in a GaAs/AlAs quantum well |
Type |
A1 Journal article |
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Year |
1993 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
47 |
Issue |
16 |
Pages |
10358-10374 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
The effects of interface optical-phonon and confined slab LO-phonon modes on the polaron cyclotron-resonance frequency are investigated for a GaAs/AlAs quantum well. Using degenerate second-order perturbation theory, the polaron Landau levels are calculated and the polaron resonant region is investigated. In order to know the relative importance of the different resonant frequencies we present a full calculation of the magneto-optical absorption spectrum. At a fixed magnetic field we found four different peaks in the absorption spectrum. The relative oscillator strength of the different peaks changes with increasing magnetic field. For comparative purposes, the polaron Landau levels and cyclotron mass are also calculated using only the bulk LO-phonon modes. The influence of the finiteness of the confinement potential is investigated. We found that the interface-phonon modes influence the magnetopolaron resonance considerably near the optical-phonon frequencies for narrow wells. In the limit of zero magnetic field we recover our previous results and in the case of an infinite-barrier quantum well we are able to recover the results for a two- and three-dimensional system. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
A1993LA29800034 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.736 |
Times cited |
69 |
Open Access |
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Notes |
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Approved |
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Call Number |
UA @ lucian @ c:irua:5739 |
Serial |
2663 |
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Author |
Xu, W.; Peeters, F.M.; Devreese, J.T. |
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Title |
Streaming-to-accumulation transition in a 2-dimensional electron-system in a polar semiconductor |
Type |
A1 Journal article |
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Year |
1992 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
46 |
Issue |
12 |
Pages |
7571-7580 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
Hot-electron transport is studied for a two-dimensional electron gas coupled to longitudinal-optical phonons in crossed electric and magnetic fields. At low electric and high magnetic fields the electrons are accumulated, while at high electric fields they are in a streaming state. We develop a streaming-to-accumulation transition model and compare the results with that from a Monte Carlo simulation. |
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Corporate Author |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
A1992JQ37800028 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.736 |
Times cited |
13 |
Open Access |
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Notes |
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Approved |
PHYSICS, APPLIED 28/145 Q1 # |
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Call Number |
UA @ lucian @ c:irua:103023 |
Serial |
3174 |
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| Permanent link to this record |
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Author |
Wen, X.; Peeters, F.M.; Devreese, J.T. |
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Title |
Streaming-to-accumulation transition in a two-dimensional electron system in a polar semiconductor |
Type |
A1 Journal article |
| |
Year |
1992 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
46 |
Issue |
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Pages |
7571-7580 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
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Address |
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Corporate Author |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
A1992JQ37800028 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.736 |
Times cited |
13 |
Open Access |
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Notes |
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Approved |
PHYSICS, APPLIED 28/145 Q1 # |
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Call Number |
UA @ lucian @ c:irua:2913 |
Serial |
3175 |
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| Permanent link to this record |
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Author |
Peeters, F.M.; Vasilopoulos, P. |
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Title |
Electrical and thermal-properties of a 2-dimensional electron-gas in a one-dimensional periodic potential |
Type |
A1 Journal article |
| |
Year |
1992 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
46 |
Issue |
8 |
Pages |
4667-4680 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We investigate the influence of a periodic weak modulation along the x direction on the electrical and thermal properties of a two-dimensional electron gas in the presence of a perpendicular magnetic field. The modulation lifts the degeneracy of the Landau levels and leads to one-dimensional magnetic bands whose bandwidth oscillates as a function of the magnetic field. At weak magnetic fields this gives rise to the Weiss oscillations in the magnetoresistance, discovered recently, which have a very weakly temperature-dependent amplitude and a period proportional to square-root n(e), when n(e) is the electron density. Diffusion-current contributions, proportional to the square of the bandwidth, dominate rho(xx), and collisional contributions, varying approximately as the square of the density of states, dominate rho(yy). The result is that rho(xx) and rho(yy) oscillate out of phase as observed. Asymptotic analytical expressions are presented for the conductivity tensor. Similar oscillations, of much smaller amplitude, occur in the thermodynamic quantities, such as the magnetization, the susceptibility, and the specific heat. We also predict oscillations in the Hall resistance, the cyclotron resonance position, the linewidth, as well as in the thermal conductivity and thermopower. The components of the thermal-resistance tensor have a magnetic-field dependence similar to that of the electrical-resistivity tensor. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
A1992JK72500032 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.736 |
Times cited |
148 |
Open Access |
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Notes |
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Approved |
INSTRUMENTS & INSTRUMENTATION 31/56 Q3 # NUCLEAR SCIENCE & TECHNOLOGY 9/32 Q2 # PHYSICS, PARTICLES & FIELDS 24/28 Q4 # SPECTROSCOPY 28/43 Q3 # |
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Call Number |
UA @ lucian @ c:irua:103028 |
Serial |
889 |
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| Permanent link to this record |
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Author |
Peeters, F.M.; Vasilopoulos, P. |
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Title |
Electrical and thermal properties of a two-dimensional electron gas in a one-dimensional periodic potential |
Type |
A1 Journal article |
| |
Year |
1992 |
Publication |
Physical review: B |
Abbreviated Journal |
Phys Rev B |
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Volume |
46 |
Issue |
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Pages |
4667-4680 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
A1992JK72500032 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.736 |
Times cited |
148 |
Open Access |
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Notes |
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Approved |
INSTRUMENTS & INSTRUMENTATION 31/56 Q3 # NUCLEAR SCIENCE & TECHNOLOGY 9/32 Q2 # PHYSICS, PARTICLES & FIELDS 24/28 Q4 # SPECTROSCOPY 28/43 Q3 # |
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Call Number |
UA @ lucian @ c:irua:2998 |
Serial |
890 |
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| Permanent link to this record |
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Author |
Backes, W.H.; Peeters, F.M.; Brosens, F.; Devreese, J.T. |
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Title |
Dispersion of longitudinal plasmons for a quasi-two-dimensional electron gas |
Type |
A1 Journal article |
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Year |
1992 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
45 |
Issue |
15 |
Pages |
8437-8442 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
Confinement of electrons in ultrathin metallic films leads to subbands. By increasing the thickness of the electron layer, the subbands will dissolve into a quasicontinuum, with the number of electrons per unit volume kept constant. Within the random-phase approximation, the two-dimensional plasmon, which originally follows Stern's dispersion relation, becomes a longitudinal surface plasmon. The plasmon excitations of a model metallic film are investigated by including all subbands. Single-particle excitations, which exhibit the depolarization shift, converge into the plasma excitation spectrum. With further increases in the film thickness, the bulk plasmon arises and the surface plasmon remains. Our analysis shows how quantum size effects evolve into hydrodynamical classical size effects with increasing thickness of the film. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
A1992HR33600028 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.736 |
Times cited |
37 |
Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ lucian @ c:irua:2738 |
Serial |
737 |
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| Permanent link to this record |
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Author |
Verbist, G.; Smondyrev, M.A.; Peeters, F.M.; Devreese, J.T. |
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Title |
Strong-coupling analysis of large bipolarons in 2 and 3 dimensions |
Type |
A1 Journal article |
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Year |
1992 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
45 |
Issue |
10 |
Pages |
5262-5269 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
In the limit of strong electron-phonon coupling, we use either a Pekar-type or an oscillator wave function for the center-of-mass coordinate and either a Coulomb or an oscillator wave function for the relative coordinate, and are able to reproduce all the results from the literature for the large-bipolaron binding energy. Lower bounds are constructed for the critical ratio eta(c) of dielectric constants below which bipolarons can exist. It is found that, in the strong-coupling limit, the stability region for bipolaron formation is much larger in two dimensions (2D) than in 3D. We introduce a model that combines the averaging of the relative coordinate over the asymptotically best wave function with a path-integral treatment of the center-of-mass motion. The stability region for bipolaron formation is increased compared with the full path-integral treatment at large values of the coupling constant alpha. The critical values are alpha(c) almost-equal-to 9.3 in 3D and alpha(c) almost-equal-to 4.5 in 2D. Phase diagrams for the presented models are also obtained in both 2D and 3D. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
A1992HJ68900016 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.736 |
Times cited |
68 |
Open Access |
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Notes |
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Approved |
PHYSICS, APPLIED 28/145 Q1 # |
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Call Number |
UA @ lucian @ c:irua:103051 |
Serial |
3178 |
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| Permanent link to this record |
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Author |
Verbist, G.; Smondyrev, M.A.; Peeters, F.M.; Devreese, J.T. |
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Title |
Strong-coupling analysis of large bipolarons in two and three dimensions |
Type |
A1 Journal article |
| |
Year |
1992 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
45 |
Issue |
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Pages |
5262-5269 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
A1992HJ68900016 |
Publication Date |
2002-07-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0163-1829 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.736 |
Times cited |
68 |
Open Access |
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Notes |
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Approved |
PHYSICS, APPLIED 28/145 Q1 # |
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Call Number |
UA @ lucian @ c:irua:2891 |
Serial |
3179 |
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| Permanent link to this record |
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Author |
Wang, J.; Zhao, W.-S.; Hu, Y.; Filho, R.N.C.; Peeters, F.M. |
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Title |
Charged vacancy in graphene : interplay between Landau levels and atomic collapse resonances |
Type |
A1 Journal article |
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Year |
2024 |
Publication |
Physical review B |
Abbreviated Journal |
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Volume |
109 |
Issue |
10 |
Pages |
104103-104106 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The interplay between a magnetic field and the Coulomb potential from a charged vacancy on the electron states in graphene is investigated within the tight-binding model. The Coulomb potential removes locally Landau level degeneracy, while the vacancy introduces a satellite level next to the normal Landau level. These satellite levels are found throughout the positive-energy region, but in the negative-energy region, they turn into atomic collapse resonances. Crossings between Landau levels with different angular quantum number m are found. Unlike the point impurity system in which an anticrossing occurs between Landau levels of the same m, in this work anticrossing is found between the normal Landau level and the vacancy-induced level. The atomic collapse resonance hybridizes with the Landau levels. The charge at which the lowest Landau level m = -1, N = 1 crosses E = 0 increases with enhancing magnetic field. A Landau level scaling anomaly occurs when the charge is larger than the critical charge beta 0.6 and this critical charge is independent of the magnetic field. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Language |
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Wos |
001199561900008 |
Publication Date |
2024-03-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.7 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 3.7; 2024 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:205508 |
Serial |
9137 |
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| Permanent link to this record |
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Author |
Moura, V.N.; Chaves, A.; Peeters, F.M.; Milošević, M.V. |
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Title |
McMillan-Ginzburg-Landau theory of singularities and discommensurations in charge density wave states of transition metal dichalcogenides |
Type |
A1 Journal article |
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Year |
2024 |
Publication |
Physical review B |
Abbreviated Journal |
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Volume |
109 |
Issue |
9 |
Pages |
094507-94511 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The McMillan-Ginzburg-Landau (MGL) model for charge density waves (CDW) is employed in a systematic phenomenological study of the different phases that have been probed in recent experiments involving transition metal dichalcogenides. We implemented an efficient imaginary time evolution method to solve the MGL equations, which enabled us to investigate the role of different coupling parameters on the CDW patterns and to perform calculations with different energy functionals that lead to several experimentally observed singularities in the CDW phase profiles. In particular, by choosing the appropriate energy functionals, we were able to obtain phases that go beyond the well-known periodic phase slips (discommensurations), exhibiting also topological defects (i.e., vortex-antivortex pairs), domain walls where the CDW order parameter is suppressed, and even CDW with broken rotational symmetry. Finally, we briefly discuss the effect of these different CDW phases on the profile and critical temperature of the competing superconducting state. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001199651500001 |
Publication Date |
2024-03-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
|
|
| |
Notes |
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Approved |
Most recent IF: 3.7; 2024 IF: 3.836 |
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| |
Call Number |
UA @ admin @ c:irua:205491 |
Serial |
9158 |
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| Permanent link to this record |
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| |
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Author |
Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V. |
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| |
Title |
Tailoring weak and metallic phases in a strong topological insulator by strain and disorder : conductance fluctuations signatures |
Type |
A1 Journal article |
| |
Year |
2024 |
Publication |
Physical review B |
Abbreviated Journal |
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|
| |
Volume |
109 |
Issue |
4 |
Pages |
045129-7 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Transport measurements are readily used to probe different phases in disordered topological insulators (TIs), where determining topological invariants explicitly is challenging. On that note, universal conductance fluctuations (UCF) theory asserts the conductance G for an ensemble has a Gaussian distribution, and that standard deviation 8G depends solely on the symmetries and dimensions of the system. Using a real-space tight -binding Hamiltonian on a system with Anderson disorder, we explore conductance fluctuations in a thin Bi2Se3 film and demonstrate the agreement of their behavior with UCF hypotheses. We further show that magnetic field applied out-of-plane breaks the time -reversal symmetry and transforms the system's Wigner-Dyson class from root symplectic to unitary, increasing 8G by 2. Finally, we reveal that while Bi2Se3 is a strong TI, weak TI and metallic phases can be stabilized in presence of strain and disorder, and detected by monitoring the conductance fluctuations. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001173938400008 |
Publication Date |
2024-01-16 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
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| |
Notes |
|
Approved |
Most recent IF: 3.7; 2024 IF: 3.836 |
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| |
Call Number |
UA @ admin @ c:irua:204765 |
Serial |
9177 |
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| Permanent link to this record |
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| |
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Author |
Santos-Castro, G.; Pandey, T.; Bruno, C.H.V.; Santos Caetano, E.W.; Milošević, M.V.; Chaves, A.; Freire, V.N. |
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| |
Title |
Silicon and germanium adamantane and diamantane monolayers as two-dimensional anisotropic direct-gap semiconductors |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Physical review B |
Abbreviated Journal |
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|
| |
Volume |
108 |
Issue |
3 |
Pages |
035302-35310 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Structural and electronic properties of silicon and germanium monolayers with two different diamondoid crystal structures are detailed ab initio. Our results show that, despite Si and Ge being well-known indirect gap semiconductors in their bulk form, their adamantane and diamantane monolayers can exhibit optically active direct gap in the visible frequency range, with highly anisotropic effective masses, depending on the monolayer crystal structure. Moreover, we reveal that gaps in these materials are highly tunable with applied strain. These stable monolayer forms of Si and Ge are therefore expected to help bridging the gap between the fast growing area of opto-electronics in two-dimensional materials and the established silicon-based technologies. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
001074455300012 |
Publication Date |
2023-07-05 |
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Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
|
|
| |
Notes |
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Approved |
Most recent IF: 3.7; 2023 IF: 3.836 |
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| |
Call Number |
UA @ admin @ c:irua:200348 |
Serial |
9089 |
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| Permanent link to this record |
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| |
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Author |
Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V. |
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Title |
High Chern number in strained thin films of dilute magnetic topological insulators |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Physical review B |
Abbreviated Journal |
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|
| |
Volume |
107 |
Issue |
19 |
Pages |
195119-6 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
The quantum anomalous Hall effect was first observed experimentally by doping the Bi2Se3 materials family with chromium, where 5% doping induces an exchange field of around 0.1 eV. In ultrathin films, a topological phase transition from a normal insulator to a Chern insulator can be induced with an exchange field proportional to the hybridization gap. Subsequent transitions to states with higher Chern numbers require an exchange field larger than the (bulk) band gap, but are prohibited in practice by the detrimental effects of higher doping levels. Here, we show that threshold doping for these phase transitions in thin films is controllable by strain. As a consequence, higher Chern states can be reached with experimentally feasible doping, sufficiently dilute for the topological insulator to remain structurally stable. Such a facilitated realization of higher Chern insulators opens prospects for multichannel quantum computing, higher-capacity circuit interconnects, and energy-efficient electronic devices at elevated temperatures. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
000995111000003 |
Publication Date |
2023-05-11 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
| |
Impact Factor |
3.7 |
Times cited |
2 |
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 3.7; 2023 IF: 3.836 |
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| |
Call Number |
UA @ admin @ c:irua:197295 |
Serial |
8820 |
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| Permanent link to this record |
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| |
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Author |
Linard, F.J.A.; Moura, V.N.; Covaci, L.; Milošević, M.V.; Chaves, A. |
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Title |
Wave-packet scattering at a normal-superconductor interface in two-dimensional materials : a generalized theoretical approach |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Physical review B |
Abbreviated Journal |
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| |
Volume |
107 |
Issue |
16 |
Pages |
165306-165309 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
A wave-packet time evolution method, based on the split-operator technique, is developed to investigate the scattering of quasiparticles at a normal-superconductor interface of arbitrary profile and shape. As a practical application, we consider a system where low-energy electrons can be described as Dirac particles, which is the case for most two-dimensional materials, such as graphene and transition-metal dichalcogenides. However, the method is easily adapted for other cases such as electrons in few-layer black phosphorus or any Schrodinger quasiparticles within the effective mass approximation in semiconductors. We employ the method to revisit Andreev reflection in mono-, bi-, and trilayer graphene, where specular-and retro-reflection cases are observed for electrons scattered by a steplike superconducting region. The effect of opening a zero-gap channel across the superconducting region on the electron and hole scattering is also addressed, as an example of the versatility of the technique proposed here. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000974675700006 |
Publication Date |
2023-04-14 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 3.7; 2023 IF: 3.836 |
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| |
Call Number |
UA @ admin @ c:irua:196709 |
Serial |
8954 |
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| Permanent link to this record |
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Author |
Ahmadkhani, S.; Alihosseini, M.; Ghasemi, S.; Ahmadabadi, I.; Hassani, N.; Peeters, F.M.; Neek-Amal, M. |
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Title |
Multiband flattening and linear Dirac band structure in graphene with impurities |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Physical review B |
Abbreviated Journal |
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| |
Volume |
107 |
Issue |
7 |
Pages |
075401-75408 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Flat bands in the energy spectrum have attracted a lot of attention in recent years because of their unique properties and promising applications. Special arrangement of impurities on monolayer graphene are proposed to generate multiflat bands in the electronic band structure. In addition to the single midgap states in the spectrum of graphene with low hydrogen density, we found closely spaced bands around the Fermi level with increasing impurity density, which are similar to discrete lines in the spectrum of quantum dots, as well as the unusual Landau-level energy spectrum of graphene in the presence of a strong magnetic field. The presence of flat bands crucially depends on whether or not there are odd or even electrons of H(F) atoms bound to graphene. Interestingly, we found that a fully hydrogenated (fluoridated) of a hexagon of graphene sheet with six hydrogen (fluorine) atoms sitting on top and bottom in consecutive order exhibits Dirac cones in the electronic band structure with a 20% smaller Fermi velocity as compared to the pristine graphene. Functionalizing graphene introduces various C-C bond lengths resulting in nonuniform strains. Such a nonuniform strain may induce a giant pseudomagnetic field in the system, resulting in quantum Hall effect. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000994364500006 |
Publication Date |
2023-02-02 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
| |
Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
OpenAccess |
|
| |
Notes |
|
Approved |
Most recent IF: 3.7; 2023 IF: 3.836 |
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| |
Call Number |
UA @ admin @ c:irua:197431 |
Serial |
8822 |
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| Permanent link to this record |
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Author |
Nulens, L.; Dausy, H.; Wyszynski, M.J.; Raes, B.; Van Bael, M.J.; Milošević, M.V.; Van de Vondel, J. |
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Title |
Metastable states and hidden phase slips in nanobridge SQUIDs |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
106 |
Issue |
13 |
Pages |
134518-134519 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We fabricated an asymmetric nanoscale SQUID consisting of one nanobridge weak link and one Dayem bridge weak link. The current phase relation of these particular weak links is characterized by multivaluedness and linearity. While the latter is responsible for a particular magnetic field dependence of the critical current (so-called vorticity diamonds), the former enables the possibility of different vorticity states (phase winding numbers) existing at one magnetic field value. In experiments the observed critical current value is stochastic in nature, does not necessarily coincide with the current associated with the lowest energy state and critically depends on the measurement conditions. In this paper, we unravel the origin of the observed metastability as a result of the phase dynamics happening during the freezing process and while sweeping the current. Moreover, we employ special measurement protocols to prepare the desired vorticity state and identify the (hidden) phase slip dynamics ruling the detected state of these nanodevices. In order to gain insights into the dynamics of the condensate and, more specifically the hidden phase slips, we performed time-dependent Ginzburg-Landau simulations. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000904657300007 |
Publication Date |
2022-10-31 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.7 |
Times cited |
1 |
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 3.7 |
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| |
Call Number |
UA @ admin @ c:irua:193393 |
Serial |
7321 |
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| Permanent link to this record |
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Author |
Lazarevic, N.; Baum, A.; Milosavljevic, A.; Peis, L.; Stumberger, R.; Bekaert, J.; Solajic, A.; Pesic, J.; Wang, A.; Scepanovic, M.; Abeykoon, A.M.M.; Milošević, M.V.; Petrovic, C.; Popovic, Z.V.; Hackl, R. |
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Title |
Evolution of lattice, spin, and charge properties across the phase diagram of Fe1-xSx |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
106 |
Issue |
9 |
Pages |
094510-94519 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
A Raman scattering study covering the entire substitution range of the FeSe1-xSx solid solution is presented. Data were taken as a function of sulfur concentration x for 0 <= x <= 1, of temperature and of scattering symmetry. All types of excitations including phonons, spins, and charges are analyzed in detail. It is observed that the energy and width of the iron-related B-1g phonon mode vary continuously across the entire range of sulfur substitution. The A(1g) chalcogenide mode disappears above x = 0.23 and reappears at a much higher energy for x = 0.69. In a similar way the spectral features appearing at finite doping in A(1g) symmetry vary discontinuously. The magnetic excitation centered at approximately 500 cm(-1) disappears above x = 0.23 where the A(1g) lattice excitations exhibit a discontinuous change in energy. The low-energy mode associated with fluctuations displays maximal intensity at the nematostructural transition and thus tracks the phase boundary. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000917933500004 |
Publication Date |
2022-09-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
|
| |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 3.7 |
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| |
Call Number |
UA @ admin @ c:irua:194397 |
Serial |
7304 |
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| Permanent link to this record |
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Author |
Moura, V.N.; Dantas, D.S.; Farias, G.A.; Chaves, A.; Milošević, M.V. |
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Title |
Latent superconductivity at parallel interfaces in a superlattice dominated by another collective quantum phase |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
106 |
Issue |
1 |
Pages |
014516-10 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We theoretically examine behavior of superconductivity at parallel interfaces separating the domains of another dominant collective excitation, such as charge density waves or spin density waves. Due to their competitive coupling in a two-component Ginzburg-Landau model, suppression of the dominant order parameter at the interfacial planes allows for nucleation of the (hidden) superconducting order parameter at those planes. In such a case, we demonstrate how the number of the parallel interfacial planes and the distance between them are linked to the number and the size of the emerging superconducting gaps in the system, as well as the versatility and temperature evolution of the possible superconducting phases. These findings bear relevance to a broad selection of known layered superconducting materials, as well as to further design of artificial (e.g., oxide) superlattices, where the interplay between competing order parameters paves the way towards otherwise unattainable superconducting states, some with enhanced superconducting critical temperature. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000834346000004 |
Publication Date |
2022-07-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 3.7 |
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| |
Call Number |
UA @ admin @ c:irua:189520 |
Serial |
7179 |
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| Permanent link to this record |
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Author |
Vizarim, N.P.; Souza, J.C.B.; Reichhardt, C.J.O.; Reichhardt, C.; Milošević, M.V.; Venegas, P.A. |
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Title |
Soliton motion in skyrmion chains : stabilization and guidance by nanoengineered pinning |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
105 |
Issue |
22 |
Pages |
224409-224412 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using a particle-based model we examine the depinning motion of solitons in skyrmion chains in quasi -onedimensional (1D) and two-dimensional (2D) systems containing embedded 1D interfaces. The solitons take the form of a particle or hole in a commensurate chain of skyrmions. Under an applied drive, just above a critical depinning threshold, the soliton moves with a skyrmion Hall angle of zero. For higher drives, the entire chain depins, and in a 2D system we observe that both the solitons and chain move at zero skyrmion Hall angle and then transition to a finite skyrmion Hall angle as the drive increases. In a 2D system with a 1D interface that is at an angle to the driving direction, there can be a reversal of the sign of the skyrmion Hall angle from positive to negative. Our results suggest that solitons in skyrmion systems could be used as information carriers in racetrack geometries that would avoid the drawbacks of finite skyrmion Hall angles. The soliton states become mobile at significantly lower drives than the depinning transition of the skyrmion chains themselves. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000823038900004 |
Publication Date |
2022-06-16 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.7 |
Times cited |
2 |
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 3.7 |
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| |
Call Number |
UA @ admin @ c:irua:189671 |
Serial |
7209 |
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| Permanent link to this record |
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Author |
Cunha, S.M.; da Costa, D.R.; Pereira, J.M., Jr.; Costa Filho, R.N.; Van Duppen, B.; Peeters, F.M. |
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Title |
Tunneling properties in α-T₃ lattices : effects of symmetry-breaking terms |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
105 |
Issue |
16 |
Pages |
165402-165414 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
The alpha-T3 lattice model interpolates a honeycomb (graphene-like) lattice and a T3 (also known as dice) lattice via the parameter alpha. These lattices are made up of three atoms per unit cell. This gives rise to an additional dispersionless flat band touching the conduction and valence bands. Electrons in this model are analogous to Dirac fermions with an enlarged pseudospin, which provides unusual tunneling features like omnidirectional Klein tunneling, also called super-Klein tunneling (SKT). However, it is unknown how small deviations in the equivalence between the atomic sites, i.e., variations in the alpha parameter, and the number of tunnel barriers changes the transmission properties. Moreover, it is interesting to learn how tunneling occurs through regions where the energy spectrum changes from linear with a middle flat band to a hyperbolic dispersion. In this paper we investigate these properties, its dependence on the number of square barriers and the alpha parameter for either gapped and gapless cases. Furthermore, we compare these results to the case where electrons tunnel from a region with linear dispersion to a region with a bandgap. In the latter case, contrary to tunneling through a potential barrier, the SKT is no longer observed. Finally, we find specific cases where transmission is allowed due to a symmetry breaking of sublattice equivalence. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000805195200001 |
Publication Date |
2022-04-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 3.7 |
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| |
Call Number |
UA @ admin @ c:irua:188614 |
Serial |
7222 |
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| Permanent link to this record |
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Author |
Mirzakhani, M.; da Costa, D.R.; Peeters, F.M. |
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Title |
Isolated and hybrid bilayer graphene quantum rings |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
105 |
Issue |
11 |
Pages |
115430-11 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using the continuum model, we investigate the electronic properties of two types of bilayer graphene (BLG) quantum ring (QR) geometries: (i) An isolated BLG QR and (ii) a monolayer graphene (MLG) with a QR put on top of an infinite graphene sheet (hybrid BLG QR). Solving the Dirac-Weyl equation in the presence of a perpendicular magnetic field and applying the infinite mass boundary condition at the ring boundaries, we obtain analytical results for the energy levels and corresponding wave spinors for both structures. In the case of isolated BLG QR, we observe a sizable and magnetically tunable band gap which agrees with the tight-binding transport simulations. Our analytical results also show the intervalley symmetry EeK (m) = ???EK??? h (m) between the electron (e) and the hole (h) states (m is the angular momentum quantum number) for the energy spectrum of the isolated BLG QR. The presence of interface boundary in a hybrid BLG QR modifies drastically the energy levels as compared with that of an isolated BLG QR. Its energy levels are tunable from MLG dot to isolated BLG QR and to MLG Landau energy levels as the magnetic field is varied. Our predictions can be verified experimentally using different techniques such as by magnetotransport measurements. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000801209300006 |
Publication Date |
2022-03-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.7 |
Times cited |
4 |
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 3.7 |
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| |
Call Number |
UA @ admin @ c:irua:188703 |
Serial |
7175 |
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| Permanent link to this record |
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Author |
Zhang, H.Y.; Xiao, Y.M.; N. Li, Q.; Ding, L.; Van Duppen, B.; Xu, W.; Peeters, F.M. |
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Title |
Anisotropic and tunable optical conductivity of a two-dimensional semi-Dirac system in the presence of elliptically polarized radiation |
Type |
A1 Journal article |
| |
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
105 |
Issue |
11 |
Pages |
115423-115429 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We investigate the effect of ellipticity ratio of the polarized radiation field on optoelectronic properties of a two-dimensional (2D) semi-Dirac (SD) system. The optical conductivity is calculated within the energy balance equation approach derived from the semiclassical Boltzmann equation. We find that there exists the anisotropic optical absorption induced via both the intra-and interband electronic transition channels in the perpendicular xx and yy directions. Furthermore, we examine the effects of the ellipticity ratio, the temperature, the carrier density, and the band-gap parameter on the optical conductivity of the 2D SD system placed in transverse and vertical directions, respectively. It is shown that the ellipticity ratio, temperature, carrier density, and band-gap parameter can play the important roles in tuning the strength, peak position, and shape of the optical conductivity spectrum. The results obtained from this study indicate that the 2D SD system can be a promising anisotropic and tunable optical and optoelectronic material for applications in innovative 2D optical and optoelectronic devices, which are active in the infrared and terahertz bandwidths. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000802810700002 |
Publication Date |
2022-03-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.7 |
Times cited |
3 |
Open Access |
OpenAccess |
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| |
Notes |
|
Approved |
Most recent IF: 3.7 |
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| |
Call Number |
UA @ admin @ c:irua:188660 |
Serial |
7125 |
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| Permanent link to this record |
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Author |
Man, L.F.; Xu, W.; Xiao, Y.M.; Wen, H.; Ding, L.; Van Duppen, B.; Peeters, F.M. |
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Title |
Terahertz magneto-optical properties of graphene hydrodynamic electron liquid |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
104 |
Issue |
12 |
Pages |
125420 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The discovery of the hydrodynamic electron liquid (HEL) in graphene [D. Bandurin et al., Science 351, 1055 (2016) and J. Crossno et al., Science 351, 1058 (2016)] has marked the birth of the solid-state HEL which can be probed near room temperature in a table-top setup. Here we examine the terahertz (THz) magneto-optical (MO) properties of a graphene HEL. Considering the case where the magnetic length l(B) = root h/eB is comparable to the mean-free path l(ee) for electron-electron interaction in graphene, the MO conductivities are obtained by taking a momentum balance equation approach on the basis of the Boltzmann equation. We find that when l(B) similar to l(ee), the viscous effect in a HEL can weaken significantly the THz MO effects such as cyclotron resonance and Faraday rotation. The upper hybrid and cyclotron resonance magnetoplasmon modes omega(+/-) are also obtained through the RPA dielectric function. The magnetoplasmons of graphene HEL at large wave-vector regime are affected by the viscous effect, and results in red-shifts of the magnetoplasmon frequencies. We predict that the viscosity in graphene HEL can affect strongly the magneto-optical and magnetoplasmonic properties, which can be verified experimentally. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000704419300004 |
Publication Date |
2021-09-15 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
4 |
Open Access |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:182518 |
Serial |
7029 |
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| Permanent link to this record |
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Author |
Cunha, S.M.; de Costa, D.R.; Pereira Jr, J.M.; Costa Filho, R.N.; Van Duppen, B.; Peeters, F.M. |
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Title |
Band-gap formation and morphing in alpha-T-3 superlattices |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
104 |
Issue |
11 |
Pages |
115409 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Electrons in alpha-T-3 lattices behave as condensed-matter analogies of integer-spin Dirac fermions. The three atoms making up the unit cell bestow the energy spectrum with an additional energy band that is completely flat, providing unique electronic properties. The interatomic hopping term, alpha, is known to strongly affect the electronic spectrum of the two-dimensional (2D) lattice, allowing it to continuously morph from graphenelike responses to the behavior of fermions in a dice lattice. For pristine lattice structures the energy bands are gapless, but small deviations in the atomic equivalence of the three sublattices will introduce gaps in the spectrum. It is unknown how these affect transport and electronic properties such as the energy spectrum of superlattice minibands. Here we investigate the dependency of these properties on the parameter a accounting for different symmetry-breaking terms, and we show how it affects band-gap formation. Furthermore, we find that superlattices can force band gaps to close and shift in energy. Our results demonstrate that alpha-T-3 superlattices provide a versatile material for 2D band-gap engineering purposes. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000696091600003 |
Publication Date |
2021-09-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:181544 |
Serial |
6972 |
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| Permanent link to this record |
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Author |
Miranda, L.P.; Milovanović, S.P.; Filho, R.N.C.; Peeters, F.M. |
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Title |
Hall and bend resistance of a phosphorene Hall bar |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
104 |
Issue |
3 |
Pages |
035401 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The dependence of the Hall and bend resistances on a perpendicular magnetic field and on vacancy defects in a four-terminal phosphorene single layer Hall bar is investigated. A tight-binding model in combination with the Landauer-Buttiker formalism is used to calculate the energy spectrum, the lead-to-lead transmissions, and the Hall and bend resistances of the system. It is shown that the terminals with zigzag edge orientation are responsible for the absence of quantized plateaus in the Hall resistance and peaks in the longitudinal resistance. A negative bend resistance in the ballistic regime is found due to the presence of high- and low-energy transport modes in the armchair and zigzag terminals, respectively. The system density of states, with single vacancy defects, shows that the presence of in-gap states is proportional to the number of vacancies. Quantized plateaus in the Hall resistance are only formed in a sufficiently clean system. The effects of different kinds of vacancies where the plateaus are destroyed and a diffusive regime appears in the bend resistance are investigated. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000669002000003 |
Publication Date |
2021-07-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
2 |
Open Access |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:179704 |
Serial |
6997 |
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Author |
Mijin, S.D.; Baum, A.; Bekaert, J.; Solajic, A.; Pesic, J.; Liu, Y.; He, G.; Milošević, M.V.; Petrovic, C.; Popovic, Z., V; Hackl, R.; Lazarevic, N. |
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Title |
Probing charge density wave phases and the Mott transition in 1T-TaS₂I by inelastic light scattering |
Type |
A1 Journal article |
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Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
103 |
Issue |
24 |
Pages |
245133 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We present a polarization-resolved, high-resolution Raman scattering study of the three consecutive charge density wave (CDW) regimes in 1T-TaS2 single crystals, supported by ab initio calculations. Our analysis of the spectra within the low-temperature commensurate (C-CDW) regime shows P (3) over bar symmetry of the system, thus excluding the previously proposed triclinic stacking of the “star-of-David” structure, and promoting trigonal or hexagonal stacking instead. The spectra of the high-temperature incommensurate (IC-CDW) phase directly project the phonon density of states due to the breaking of the translational invariance, supplemented by sizable electron-phonon coupling. Between 200 and 352 K, our Raman spectra show contributions from both the IC-CDW and the C-CDW phases, indicating their coexistence in the so-called nearly commensurate (NC-CDW) phase. The temperature dependence of the symmetry-resolved Raman conductivity indicates the stepwise reduction of the density of states in the CDW phases, followed by a Mott transition within the C-CDW phase. We determine the size of the Mott gap to be Omega(gap) approximate to 170-190 meV, and track its temperature dependence. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000664450500002 |
Publication Date |
2021-06-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
4 |
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:179664 |
Serial |
7015 |
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| Permanent link to this record |
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Author |
Motta, M.; Burger, L.; Jiang, L.; Acosta, J.D.G.; Jelić, Ž.L.; Colauto, F.; Ortiz, W.A.; Johansen, T.H.; Milošević, M.V.; Cirillo, C.; Attanasio, C.; Xue, C.; Silhanek, A., V.; Vanderheyden, B. |
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Title |
Metamorphosis of discontinuity lines and rectification of magnetic flux avalanches in the presence of noncentrosymmetric pinning forces |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
103 |
Issue |
22 |
Pages |
224514 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Considering a noncentrosymmetric pinning texture composed of a square array of triangular holes, the magnetic flux penetration and expulsion are investigated experimentally and theoretically. A direct visualization of the magnetic landscape obtained using a magneto-optical technique on a Nb film is complemented by a multiscale numerical modeling. This combined approach allows the magnetic flux dynamics to be identified from the single flux quantum limit up to the macroscopic electromagnetic response. Within the theoretical framework provided by time-dependent Ginzburg-Landau simulations, an estimation of the in-plane current anisotropy is obtained and its dependence with the radius of the curvature of hole vertices is addressed. These simulations show that current crowding plays an important role in channeling the flux motion, favoring hole-to-hole flux hopping rather than promoting interstitial flux displacement in between the holes. The resulting anisotropy of the critical current density gives rise to a distinct pattern of discontinuity lines for increasing and decreasing applied magnetic fields, in sharp contrast to the invariable patterns reported for centrosymmetric pinning potentials. This observation is partially accounted for by the rectification effect, as demonstrated by finite-element modeling. At low temperatures, where magnetic field penetration is dominated by thermomagnetic instabilities, highly directional magnetic flux avalanches with a fingerlike shape are observed to propagate along the easy axis of the pinning potential. This morphology is reproduced by numerical simulations. Our findings demonstrate that anisotropic pinning landscapes and, in particular, ratchet potentials produce subtle modifications to the critical state field profile that are reflected in the distribution of discontinuity lines. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000687246200001 |
Publication Date |
2021-06-09 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
OpenAccess |
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Notes |
|
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:181714 |
Serial |
7002 |
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| Permanent link to this record |
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Author |
Bacaksiz, C.; Šabani, D.; Menezes, R.M.; Milošević, M.V. |
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Title |
Distinctive magnetic properties of CrI3 and CrBr3 monolayers caused by spin-orbit coupling |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
103 |
Issue |
12 |
Pages |
125418 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
After the discovery of magnetism in monolayer CrI3, the magnetic properties of different 2D materials from the chromium-trihalide family are intuitively assumed to be similar, yielding magnetic anisotropy from the spin-orbit coupling on halide ligands. Here we reveal significant differences between the CrI3 and CrBr3 magnetic monolayers in their magnetic anisotropy, resulting Curie temperature, hysteresis in external magnetic field, and evolution of magnetism with strain, all predominantly attributed to distinctly different interplay of atomic contributions to spin-orbit coupling in two materials. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000646179300003 |
Publication Date |
2021-03-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
18 |
Open Access |
OpenAccess |
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| |
Notes |
Fonds Wetenschappelijk Onderzoek; Universiteit Antwerpen; |
Approved |
Most recent IF: 3.836 |
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Call Number |
CMT @ cmt @c:irua:177506 |
Serial |
6756 |
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| Permanent link to this record |
