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Author | Sanchez-Barriga, J.; Aguilera, I.; Yashina, L., V; Tsukanova, D.Y.; Freyse, F.; Chaika, A.N.; Callaert, C.; Abakumov, A.M.; Hadermann, J.; Varykhalov, A.; Rienks, E.D.L.; Bihlmayer, G.; Blugel, S.; Rader, O. | ||||
Title | Anomalous behavior of the electronic structure of (Bi1-xInx)2Se3across the quantum phase transition from topological to trivial insulator | Type | A1 Journal article | ||
Year | 2018 | Publication | Physical review B | Abbreviated Journal | |
Volume | 98 | Issue | 23 | Pages | 235110 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | Using spin- and angle-resolved photoemission spectroscopy and relativistic many-body calculations, we investigate the evolution of the electronic structure of (Bi1-xInx)(2)Se-3)(2)Se-3 bulk single crystals around the critical point of the trivial to topological insulator quantum-phase transition. By increasing x, we observe how a surface gap opens at the Dirac point of the initially gapless topological surface state of Bi2Se3, leading to the existence of massive fermions. The surface gap monotonically increases for a wide range of x values across the topological and trivial sides of the quantum-phase transition. By means of photon-energy-dependent measurements, we demonstrate that the gapped surface state survives the inversion of the bulk bands which occurs at a critical point near x = 0.055. The surface state exhibits a nonzero in-plane spin polarization which decays exponentially with increasing x, and which persists in both the topological and trivial insulator phases. Our calculations reveal qualitative agreement with the experimental results all across the quantum-phase transition upon the systematic variation of the spin-orbit coupling strength. A non-time-reversal symmetry-breaking mechanism of bulk-mediated scattering processes that increase with decreasing spin-orbit coupling strength is proposed as explanation. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000452322800003 | Publication Date | 2018-12-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | Open Access | |||
Notes | Approved | no | |||
Call Number | UA @ admin @ c:irua:156240 | Serial | 7462 | ||
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Author | Ozbal, G.; Senger, R.T.; Sevik, C.; Sevincli, H. | ||||
Title | Ballistic thermoelectric properties of monolayer semiconducting transition metal dichalcogenides and oxides | Type | A1 Journal article | ||
Year | 2019 | Publication | Physical review B | Abbreviated Journal | |
Volume | 100 | Issue | 8 | Pages | 085415 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Combining first-principles calculations with Landauer-Mittiker formalism, ballistic thermoelectric transport properties of semiconducting two-dimensional transition metal dichalcogenides (TMDs) and oxides (TMOs) (namely MX2 with M = Cr, Mo, W, Ti, Zr, Hf; X = O, S, Se, Te) are investigated in their 2H and 1T phases. Having computed structural, as well as ballistic electronic and phononic transport properties for all structures, we report the thermoelectric properties of the semiconducting ones. We find that 2H phases of four of the studied structures have very promising thermoelectric properties, unlike their 1T phases. The maximum room temperature p-type thermoelectric figure of merit (ZT) of 1.57 is obtained for 2H-HfSe2, which can be as high as 3.30 at T = 800 K. Additionally, 2H-ZrSe2, 2H-ZrTe2, and 2H-HfS2 have considerable ZT values (both nand p-type), that are above 1 at room temperature. The 1T phases of Zr and Hf-based oxides possess relatively high power factors, however their high lattice thermal conductance values limit their ZT values to below 1 at room temperature. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000480389100007 | Publication Date | 2019-08-12 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | Open Access | |||
Notes | Approved | no | |||
Call Number | UA @ admin @ c:irua:193773 | Serial | 7549 | ||
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Author | Takatsu, H.; Hernandez, O.; Yoshimune, W.; Prestipino, C.; Yamamoto, T.; Tassel, C.; Kobayashi, Y.; Batuk, D.; Shibata, Y.; Abakumov, A.M.; Brown, C.M.; Kageyama, H. | ||||
Title | Cubic lead perovskite PbMoO3 with anomalous metallic behavior | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical review B | Abbreviated Journal | |
Volume | 95 | Issue | 15 | Pages | 155105 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
Abstract | A previously unreported Pb-based perovskite PbMoO3 is obtained by high-pressure and high-temperature synthesis. This material crystallizes in the Pm3m cubic structure at room temperature, making it distinct from typical Pb-based perovskite oxides with a structural distortion. PbMoO3 exhibits a metallic behavior down to 0.1 K with an unusual T-sublinear dependence of the electrical resistivity. Moreover, a large specific heat is observed at low temperatures accompanied by a peak in C-P/T-3 around 10 K, in marked contrast to the isostructural metallic system SrMoO3. These transport and thermal properties for PbMoO3, taking into account anomalously large Pb atomic displacements detected through diffraction experiments, are attributed to a low-energy vibrational mode, associated with incoherent off-centering of lone-pair Pb2+ cations. We discuss the unusual behavior of the electrical resistivity in terms of a polaronlike conduction, mediated by the strong coupling between conduction electrons and optical phonons of the local low-energy vibrational mode. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000440605700001 | Publication Date | 2017-04-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | Open Access | |||
Notes | Approved | no | |||
Call Number | UA @ admin @ c:irua:167288 | Serial | 7743 | ||
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Author | Mirzakhani, M.; Zarenia, M.; Vasilopoulos, P.; Peeters, F.M. | ||||
Title | Electrostatically confined trilayer graphene quantum dots | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical review B | Abbreviated Journal | |
Volume | 95 | Issue | 15 | Pages | 155434 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Electrically gating of trilayer graphene (TLG) opens a band gap offering the possibility to electrically engineer TLG quantum dots. We study the energy levels of such quantum dots and investigate their dependence on a perpendicular magnetic field B and different types of stacking of the graphene layers. The dots are modeled as circular and confined by a truncated parabolic potential which can be realized by nanostructured gates or position-dependent doping. The energy spectra exhibit the intervalley symmetry E-K(e) (m) = -E (h)(K') (m) for the electron (e) and hole (h) states, where m is the angular momentum quantum number and K and K' label the two valleys. The electron and hole spectra for B = 0 are twofold degenerate due to the intervalley symmetry E-K (m) = E-K' [-(m + 1)]. For both ABC [alpha = 1.5 (1.2) for large (small) R] and ABA (alpha = 1) stackings, the lowest-energy levels show approximately a R-alpha dependence on the dot radius R in contrast with the 1/R-3 one for ABC-stacked dots with infinite-mass boundary. As functions of the field B, the oscillator strengths for dipole-allowed transitions differ drastically for the two types of stackings. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 000399797200003 | Publication Date | 2017-04-22 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | 6 | Open Access | ||
Notes | Approved | no | |||
Call Number | UA @ admin @ c:irua:152652 | Serial | 7878 | ||
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Author | Shayeganfar, F.; Vasu, K.S.; Nair, R.R.; Peeters, F.M.; Neek-Amal, M. | ||||
Title | Monolayer alkali and transition-metal monoxides : MgO, CaO, MnO, and NiO | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical review B | Abbreviated Journal | |
Volume | 95 | Issue | 14 | Pages | 144109 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Two-dimensional crystals with strong interactions between layers has attracted increasing attention in recent years in a variety of fields. In particular, the growth of a single layer of oxide materials (e.g., MgO, CaO, NiO, and MnO) over metallic substrates were found to display different physical properties than their bulk. In this study, we report on the physical properties of a single layer of metallic oxide materials and compare their properties with their bulk and other two-dimensional (2D) crystals. We found that the planar structure of metallic monoxides are unstable whereas the buckled structures are thermodynamically stable. Also, the 2D-MnO and NiO exhibit different magnetic (ferromagnetic) and optical properties than their bulk, whereas band-gap energy and linear stiffness are found to be decreasing from NiO to MgO. Our findings provide insight into oxide thin-film technology applications. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000399792400001 | Publication Date | 2017-04-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | 21 | Open Access | ||
Notes | Approved | no | |||
Call Number | UA @ admin @ c:irua:152654 | Serial | 8278 | ||
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Author | Mobaraki, A.; Sevik, C.; Yapicioglu, H.; Cakir, D.; Gulseren, O. | ||||
Title | Temperature-dependent phonon spectrum of transition metal dichalcogenides calculated from the spectral energy density: Lattice thermal conductivity as an application | Type | A1 Journal article | ||
Year | 2019 | Publication | Physical review B | Abbreviated Journal | |
Volume | 100 | Issue | 3 | Pages | 035402 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Predicting the mechanical and thermal properties of quasi-two-dimensional (2D) transition metal dichalco-genides (TMDs) is an essential task necessary for their implementation in device applications. Although rigorous density-functional-theory-based calculations are able to predict mechanical and electronic properties, mostly they are limited to zero temperature. Classical molecular dynamics facilitates the investigation of temperature-dependent properties, but its performance highly depends on the potential used for defining interactions between the atoms. In this study, we calculated temperature-dependent phonon properties of single-layer TMDs, namely, MoS2, MoSe2, WS2, and WSe2, by utilizing Stillinger-Weber-type potentials with optimized sets of parameters with respect to the first-principles results. The phonon lifetimes and contribution of each phonon mode in thermal conductivities in these monolayer crystals are systematically investigated by means of the spectralenergy-density method based on molecular dynamics simulations. The obtained results from this approach are in good agreement with previously available results from the Green-Kubo method. Moreover, detailed analysis of lattice thermal conductivity, including temperature-dependent mode decomposition through the entire Brillouin zone, shed more light on the thermal properties of these 2D crystals. The LA and TA acoustic branches contribute most to the lattice thermal conductivity, while ZA mode contribution is less because of the quadratic dispersion around the Brillouin zone center, particularly in MoSe2 due to the phonon anharmonicity, evident from the redshift, especially in optical modes, by increasing temperature. For all the considered 2D crystals, the phonon lifetime values are compelled by transition metal atoms, whereas the group velocity spectrum is dictated by chalcogen atoms. Overall, the lattice thermal conductivity is linearly proportional with inverse temperature. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000473536400003 | Publication Date | 2019-07-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | Times cited | Open Access | |||
Notes | Approved | no | |||
Call Number | UA @ admin @ c:irua:193764 | Serial | 8645 | ||
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Author | Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V. | ||||
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 | |
Volume | 107 | Issue | 19 | Pages | 195119-6 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
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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Publisher | Place of Publication | Editor | |||
Language | Wos | 000995111000003 | Publication Date | 2023-05-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
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 | |||
Call Number | UA @ admin @ c:irua:197295 | Serial | 8820 | ||
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Author | Ahmadkhani, S.; Alihosseini, M.; Ghasemi, S.; Ahmadabadi, I.; Hassani, N.; Peeters, F.M.; Neek-Amal, M. | ||||
Title | Multiband flattening and linear Dirac band structure in graphene with impurities | Type | A1 Journal article | ||
Year | 2023 | Publication | Physical review B | Abbreviated Journal | |
Volume | 107 | Issue | 7 | Pages | 075401-75408 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
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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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000994364500006 | Publication Date | 2023-02-02 | |
Series Editor | Series Title | Abbreviated Series Title | |||
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 | 1 | Open Access | OpenAccess |
Notes | Approved | Most recent IF: 3.7; 2023 IF: 3.836 | |||
Call Number | UA @ admin @ c:irua:197431 | Serial | 8822 | ||
Permanent link to this record | |||||
Author | Zuniga-Puelles, E.; Levytskyi, V.; Özden, A.; Guerel, T.; Bulut, N.; Himcinschi, C.; Sevik, C.; Kortus, J.; Gumeniuk, R. | ||||
Title | Thermoelectric properties and scattering mechanisms in natural PbS | Type | A1 Journal article | ||
Year | 2023 | Publication | Physical review B | Abbreviated Journal | |
Volume | 107 | Issue | 19 | Pages | 195203-195215 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | X-ray diffraction and energy dispersive x-ray spectroscopic analyses showed a natural galena (PbS) crystal from Freiberg in Saxony (Germany) to be a single phase specimen [rock salt (NaCl) structure type, space group Fm3m, a = 5.932(1) angstrom] with stoichiometric composition and an enhanced dislocation density (8 approximate to 1011 cm-2). The latter parameter leads to an increase of the electrical resistivity in the high-temperature regime, as well as to the appearance of phonon resonance with a characteristic frequency coPR = 3.8(1) THz. Being in the same range (i.e., 3-5.5 THz) with the sulfur optical modes of highest group velocities, it results in a drastic reduction (by similar to 75%) of thermal conductivity (K) at lower temperatures (i.e., < 100 K), as well as in the appearance of a characteristic minimum in K at T approximate to 30 K. Furthermore, the studied galena is characterized by phonon-drag behavior and by temperature dependent switch of the charge carrier scattering mechanism regime (i.e., scattering on dislocations for T < 100 K, on acoustic phonons for 100 K < T < 170 K and on both acoustic and optical phonons for 170 K < T < 300 K). The combined theoretical calculation and optical spectroscopic study confirm this mineral to be a direct gap degenerate semiconductor. The possible origins of the second-order Raman spectrum are discussed. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 001009980400008 | Publication Date | 2023-05-30 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
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 | Not_Open_Access | |
Notes | Approved | Most recent IF: 3.7; 2023 IF: 3.836 | |||
Call Number | UA @ admin @ c:irua:197808 | Serial | 8943 | ||
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Author | Linard, F.J.A.; Moura, V.N.; Covaci, L.; Milošević, M.V.; Chaves, A. | ||||
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 | |
Volume | 107 | Issue | 16 | Pages | 165306-165309 |
Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
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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Publisher | Place of Publication | Editor | |||
Language | Wos | 000974675700006 | Publication Date | 2023-04-14 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
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 | |||
Call Number | UA @ admin @ c:irua:196709 | Serial | 8954 | ||
Permanent link to this record | |||||
Author | Bekaert, J. | ||||
Title | Phonon-mediated superconductivity in ternary silicides X₄ CoSi (X = Nb, Ta) | Type | A1 Journal article | ||
Year | 2023 | Publication | Physical review B | Abbreviated Journal | |
Volume | 108 | Issue | 13 | Pages | 134504-134507 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The superconducting properties of two recently synthesized ternary silicides with unit formula X<sub>4</sub>CoSi (X = Nb, Ta) are investigated through ab initio calculations combined with Eliashberg theory. Interestingly, their crystal structure comprises interlocking honeycomb networks of Nb/Ta atoms. Nb<sub>4</sub>CoSi is found to harbor better conditions for phonon-mediated superconductivity, as it possesses a higher density of states at the Fermi level, fostering stronger electron-phonon coupling. The superconducting critical temperatures (T<sub>c</sub>) follow the same trend, with Nb<sub>4</sub>CoSi having a twice higher value than Ta<sub>4</sub>CoSi. Furthermore, the calculated T<sub>c</sub> values (5.9 K vs 3.1 K) agree excellently with the experimentally obtained ones, establishing superconductivity in this new materials class as mediated by the electron-phonon coupling. Furthermore, my calculations show that the superconducting properties of these compounds do not simply correlate with the parameters of their honeycomb networks, contrary to proposals raised in the literature. Rather, their complete fermiology and phonon spectrum should be taken into account in order to explain their respective superconducting properties. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 001140080300003 | Publication Date | 2023-10-17 | |
Series Editor | Series Title | Abbreviated Series Title | |||
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 | Open Access | ||
Notes | Approved | Most recent IF: 3.7; 2023 IF: 3.836 | |||
Call Number | UA @ admin @ c:irua:201445 | Serial | 9071 | ||
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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. | ||||
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 | |
Volume | 108 | Issue | 3 | Pages | 035302-35310 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
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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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 001074455300012 | Publication Date | 2023-07-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
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 | Open Access | ||
Notes | Approved | Most recent IF: 3.7; 2023 IF: 3.836 | |||
Call Number | UA @ admin @ c:irua:200348 | Serial | 9089 | ||
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Author | Lima, I.L.C.; Milošević, M.V.; Peeters, F.M.; Chaves, A. | ||||
Title | Tuning of exciton type by environmental screening | Type | A1 Journal article | ||
Year | 2023 | Publication | Physical review B | Abbreviated Journal | |
Volume | 108 | Issue | 11 | Pages | 115303-115308 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We theoretically investigate the binding energy and electron-hole (e-h) overlap of excitonic states confined at the interface between two-dimensional materials with type-II band alignment, i.e., with lowest conduction and highest valence band edges placed in different materials, arranged in a side-by-side planar heterostructure. We propose a variational procedure within the effective mass approximation to calculate the exciton ground state and apply our model to a monolayer MoS2/WS2 heterostructure. The role of nonabrupt interfaces between the materials is accounted for in our model by assuming a WxMo1-xS2 alloy around the interfacial region. Our results demonstrate that (i) interface-bound excitons are energetically favorable only for small interface thickness and/or for systems under high dielectric screening by the materials surrounding the monolayer, and that (ii) the interface exciton binding energy and its e-h overlap are controllable by the interface width and dielectric environment. | ||||
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Publisher | Place of Publication | Editor | |||
Language | Wos | 001077758300002 | Publication Date | 2023-09-08 | |
Series Editor | Series Title | Abbreviated Series Title | |||
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 | 1 | Open Access | |
Notes | Approved | Most recent IF: 3.7; 2023 IF: 3.836 | |||
Call Number | UA @ admin @ c:irua:200356 | Serial | 9110 | ||
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Author | Wang, J.; Zhao, W.-S.; Hu, Y.; Filho, R.N.C.; Peeters, F.M. | ||||
Title | Charged vacancy in graphene : interplay between Landau levels and atomic collapse resonances | Type | A1 Journal article | ||
Year | 2024 | Publication | Physical review B | Abbreviated Journal | |
Volume | 109 | Issue | 10 | Pages | 104103-104106 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
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 | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 001199561900008 | Publication Date | 2024-03-04 | |
Series Editor | Series Title | Abbreviated Series Title | |||
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 | Open Access | ||
Notes | Approved | Most recent IF: 3.7; 2024 IF: 3.836 | |||
Call Number | UA @ admin @ c:irua:205508 | Serial | 9137 | ||
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Author | Pascucci, F.; Conti, S.; Perali, A.; Tempère, J.; Neilson, D. | ||||
Title | Effects of intralayer correlations on electron-hole double-layer superfluidity | Type | A1 Journal article | ||
Year | 2024 | Publication | Physical review B | Abbreviated Journal | |
Volume | 109 | Issue | 9 | Pages | 094512-94515 |
Keywords | A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) | ||||
Abstract | We investigate the intralayer correlations acting within the layers in a superfluid system of electron -hole spatially separated layers. In this system, superfluidity is predicted to be almost exclusively confined to the Bose-Einstein condensate (BEC) and crossover regimes where the electron -hole pairs are well localized. In this case, Hartree-Fock is an excellent approximation for the intralayer correlations. We find in the BEC regime that the effect of the intralayer correlations on superfluid properties is negligible but in the BCS-BEC crossover regime the superfluid gap is significantly weakened by the intralayer correlations. This is caused by the intralayer correlations boosting the number of low -energy particle -hole excitations that drive the screening. We further find that the intralayer correlations suppress the predicted phenomenon in which the average pair size passes through a minimum as the crossover regime is traversed. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 001199662600001 | Publication Date | 2024-03-18 | |
Series Editor | Series Title | Abbreviated Series Title | |||
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 | Open Access | ||
Notes | Approved | Most recent IF: 3.7; 2024 IF: 3.836 | |||
Call Number | UA @ admin @ c:irua:205476 | Serial | 9145 | ||
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Author | Moura, V.N.; Chaves, A.; Peeters, F.M.; Milošević, M.V. | ||||
Title | McMillan-Ginzburg-Landau theory of singularities and discommensurations in charge density wave states of transition metal dichalcogenides | Type | A1 Journal article | ||
Year | 2024 | Publication | Physical review B | Abbreviated Journal | |
Volume | 109 | Issue | 9 | Pages | 094507-94511 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
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. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 001199651500001 | Publication Date | 2024-03-11 | |
Series Editor | Series Title | Abbreviated Series Title | |||
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 | Open Access | ||
Notes | Approved | Most recent IF: 3.7; 2024 IF: 3.836 | |||
Call Number | UA @ admin @ c:irua:205491 | Serial | 9158 | ||
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Author | Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V. | ||||
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 | |
Volume | 109 | Issue | 4 | Pages | 045129-7 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
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. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 001173938400008 | Publication Date | 2024-01-16 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
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 | |
Notes | Approved | Most recent IF: 3.7; 2024 IF: 3.836 | |||
Call Number | UA @ admin @ c:irua:204765 | Serial | 9177 | ||
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Author | N. Gauquelin, E. Benckiser, M. K. Kinyanjui, M. Wu, Y. Lu, G. Christiani, G. Logvenov, H.-U. Habermeier, U. Kaiser, B. Keimer, and G. A. Botton | ||||
Title | Atomically resolved EELS mapping of the interfacial structure of epitaxially strained LaNiO3/LaAlO3 superlattices | Type | A1 Journal Article | ||
Year | 2014 | Publication | Physical Review B | Abbreviated Journal | |
Volume | 90 | Issue | Pages | 195140 | |
Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
Abstract | The interfacial atomic structure of a metallic LaNiO3/LaAlO3 superlattice grown on a LaSrAlO4 substrate was investigated using a combination of atomically resolved electron energy loss spectroscopy (EELS) at the Al K, Al L2,3, Sr L2,3, Ni L2,3, La M4,5, and O K edges as well as hybridization mapping of selected features of the O K-edge fine structure.We observe an additional La1−xSrxAl1−yNiyO3 layer at the substrate-superlattice interface, possibly linked to diffusion of Al and Sr into the growing film or a surface reconstruction due to Sr segregation. The roughness of the LaNiO3/LaAlO3 interfaces is found to be on average around one pseudocubic unit cell. The O K-edge EELS spectra revealed reduced spectral weight of the prepeak derived from Ni-O hybridized states in the LaNiO3 layers. We rule out oxygen nonstoichiometry of the LaNiO3 layers and discuss changes in the Ni-O hybridization due to heterostructuring as possible origin. |
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Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000345467000003 | Publication Date | 2014-11-20 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | ISBN | Additional Links | |||
Impact Factor | Times cited | 17 | Open Access | ||
Notes | Approved | Most recent IF: NA | |||
Call Number | EMAT @ emat @ | Serial | 4544 | ||
Permanent link to this record | |||||
Author | Nogaret, A.; Lambert, N.J.; Peeters, F.M. | ||||
Title | Electrically induced spin resonance fluorescence : 2 : fluorescence spectra | Type | A1 Journal article | ||
Year | 2007 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
Volume | 76 | Issue | 7 | Pages | |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | We model the fluorescence spectra of planar spin oscillators to find conditions that maximize spin resonance fluorescence. Spin oscillators perform Rabi oscillations under the effect of a periodic effective magnetic field caused by the winding motion of an electron in a gradient of magnetic field. We show that, despite the weak coupling of the spin magnetic dipole to the vacuum, spin oscillators excited by a direct current output a few nanowatts of microwave power, which is comparable to the best microwave sources. The large quantum efficiency relies on the combination of two effects. On the one hand, the spontaneous emission rate is enhanced by the synchronization of spin oscillators, which interact through the microwave field that they emit. On the other hand, the huge Rabi frequencies experienced by spin oscillators promote spins into upper levels of Zeeman transitions, from which a radiative cascade is triggered. We demonstrate different regimes of fluorescence which correspond to different values of the Rabi period relative to the spontaneous decay time and to the oscillator dwell time in the gradient of magnetic field. We investigate the device parameters which make these regimes experimentally accessible and find conditions that optimize microwave output. We find that microwave emission is centered around the cutoff frequency of spin oscillators. This has the advantage that the peak emission frequency may be tuned from zero continuously up to a few hundred gigahertz using an electrostatic gate. Quite remarkably for a spintronics effect, electrically induced spin resonance fluorescence does not require the injection of a spin polarized current. In fact, we show that microwave spectra are mostly independent of the incoming spin polarization except for magnetic waveguides which are shorter than a certain critical length, which we will specify. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000249155300092 | Publication Date | 2007-08-09 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 8 | Open Access | |
Notes | Approved | Most recent IF: 3.836; 2007 IF: 3.172 | |||
Call Number | UA @ lucian @ c:irua:66118 | Serial | 898 | ||
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Author | Shi, J.M.; Koenraad, P.M.; van de Stadt, A.F.W.; Peeters, F.M.; Devreese, J.T.; Wolter, J.H. | ||||
Title | Electronic structure of a Si \delta-doped layer in a GaAs/AlxGa1-xAs/GaAs quantum barrier | Type | A1 Journal article | ||
Year | 1996 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
Volume | 54 | Issue | 11 | Pages | 7996-8004 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems | ||||
Abstract | We present a theoretical study of the electronic structure of a heavily Si delta-doped layer in a GaAs/AlxGa1-xAs/GaAs quantum barrier. In this class of structures the effect of DX centers on the electronic properties can be tuned by changing the AlxGa1-xAs barrier width and/or the Al concentration, which leads to a lowering of the DX level with respect to the Fermi energy without disturbing the wave functions much. A self-consistent approach is developed in which the effective confinement potential and the Fermi energy of the system, the energies, the wave functions, and the electron densities of the discrete subbands have been obtained as a function of both the material parameters of the samples and the experimental conditions. The effect of DX centers on such structures at nonzero temperature and under an external pressure is investigated for three different models: (1) the DX(nc)(0) model with no correlation effects, (2) the d(+)/DX(0) model, and (3) the d(+)/DX(-) model with inclusion of correlation effects. In the actual calculation, influences of the background accepters, the discontinuity of the effective mass of the electrons at the interfaces of the different materials, band nonparabolicity, and the exchange-correlation energy of the electrons have been taken into account. We have found that (1) introducing a quantum barrier into delta-doped GaAs makes it possible to control the energy gaps between different electronic; subbands; (2) the electron wave functions are mon spread out when the repellent effect of the barriers is increased as compared to those in delta-doped GaAs; (3) increasing the quantum-barrier height and/or the application of hydrostatic pressure are helpful to experimentally observe the effect of the DX centers through a decrease of the total free-electron density; and (4) the correlation effects of the charged impurities are important for the systems under study. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | A1996VL14500066 | Publication Date | 2002-07-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0163-1829;1095-3795; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.736 | Times cited | 11 | Open Access | |
Notes | Approved | no | |||
Call Number | UA @ lucian @ c:irua:104388 | Serial | 1012 | ||
Permanent link to this record | |||||
Author | Lamoen, D.; Ballone, P.; Parrinello, M. | ||||
Title | Electronic structure, screening and charging effects at a metal/organic tunneling junction: a first principles study | Type | A1 Journal article | ||
Year | 1996 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 54 | Issue | Pages | 5097 | |
Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | A1996VE48800102 | Publication Date | 0000-00-00 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121; 0163-1829 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.736 | Times cited | 33 | Open Access | |
Notes | Approved | PHYSICS, CONDENSED MATTER 16/67 Q1 # | |||
Call Number | UA @ lucian @ c:irua:15820 | Serial | 1018 | ||
Permanent link to this record | |||||
Author | Rosenauer, A.; Schowalter, M.; Glas, F.; Lamoen, D. | ||||
Title | First-principles calculations of 002 structure factors for electron scattering in strained InxGa1-xAs | Type | A1 Journal article | ||
Year | 2005 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
Volume | 72 | Issue | 8 | Pages | 1-10 |
Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
Abstract | This work provides values of electron scattering 002 structure factors for InxGa1-xAs as a function of the In concentration x=0 to 1. These results allow accurate compositional analysis of pseudomorphically grown InxGa1-xAs/GaAs layers by transmission electron microscopy methods relying on the chemical sensitivity of the (002) beam. The calculations go beyond the limits of the isolated atom approximation, because they take into account charge redistribution effects between atomic sites in the crystal, strain, and static atomic displacements. The computations were performed by the full potential linearized augmented plane-wave method using a generalized gradient approximation for the exchange and correlation part of the potential. The calculations of strained InxGa1-xAs correspond to the strain state in specimens with large, small, and intermediate thickness in the electron beam direction. Additionally, the effect of static atomic displacements is taken into account. All results are listed in a parameterized form. The calculated 002 structure factor vanishes at an In concentration of 16.4%. This value is in a good agreement with previously reported experimental measurements. Hence, our results are a significant improvement with respect to the isolated atom approximation which is conventionally applied in transmission electron microscopy simulations, and which predicts a value of 22.5%. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000231564600106 | Publication Date | 2005-08-12 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 42 | Open Access | |
Notes | Approved | Most recent IF: 3.836; 2005 IF: 3.185 | |||
Call Number | UA @ lucian @ c:irua:54918 | Serial | 1201 | ||
Permanent link to this record | |||||
Author | Shields, P.A.; Nicholas, R.J.; Peeters, F.M.; Beaumont, B.; Gibart, P. | ||||
Title | Free-carrier effects in gallium nitride epilayers: Valence-band dispersion | Type | A1 Journal article | ||
Year | 2001 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
Volume | 64 | Issue | 8 | Pages | 155303 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | The dispersion of the A-valence-band in GaN has been deduced from the observation of high-index magnetoexcitonic states in polarized interband magnetoreflectivity and is found to be strongly nonparabolic with a mass in the range 1.2-1.8m(e). It matches the theory of Kim et al. [Phys. Rev. B 56, 7363 (1997)] extremely well, which also gives a strong k-dependent A-valence-band mass. A strong phonon coupling leads to quenching of the observed transitions at about an LO-phonon energy above the band gap and a strong nonparabolicity. The valence band was deduced from subtracting from the reduced dispersion the electron contribution with a model that includes a full treatment of the electron-phonon interaction. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000170623000005 | Publication Date | 2002-07-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0163-1829;1095-3795; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 13 | Open Access | |
Notes | Approved | Most recent IF: 3.836; 2001 IF: NA | |||
Call Number | UA @ lucian @ c:irua:37288 | Serial | 1274 | ||
Permanent link to this record | |||||
Author | Leys, F.E.; March, N.H.; Lamoen, D. | ||||
Title | High pressure limiting forms of the zero-temperature equations of state of Ta and Pu from relativistic Thomas-Fermi theory | Type | A1 Journal article | ||
Year | 2003 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
Volume | 67 | Issue | Pages | 064109 | |
Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000181501100021 | Publication Date | 2003-03-01 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0163-1829;1095-3795; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 1 | Open Access | |
Notes | Approved | Most recent IF: 3.836; 2003 IF: NA | |||
Call Number | UA @ lucian @ c:irua:45628 | Serial | 1439 | ||
Permanent link to this record | |||||
Author | Stosic, D.; Mulkers, J.; Van Waeyenberge, B.; Ludermir, T.B.; Milošević, M.V. | ||||
Title | Paths to collapse for isolated skyrmions in few-monolayer ferromagnetic films | Type | A1 Journal article | ||
Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
Volume | 95 | Issue | 21 | Pages | 214418 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Magnetic skyrmions are topological spin configurations in materials with chiral Dzyaloshinskii-Moriya interaction (DMI), that are potentially useful for storing or processing information. To date, DMI has been found in few bulk materials, but can also be induced in atomically thin magnetic films in contact with surfaces with large spin-orbit interactions. Recent experiments have reported that isolated magnetic skyrmions can be stabilized even near room temperature in few-atom-thick magnetic layers sandwiched between materials that provide asymmetric spin-orbit coupling. Here we present the minimum-energy path analysis of three distinct mechanisms for the skyrmion collapse, based on ab initio input and the performed atomic-spin simulations. We focus on the stability of a skyrmion in three atomic layers of Co, either epitaxial on the Pt(111) surface or within a hybrid multilayer where DMI nontrivially varies per monolayer due to competition between different symmetry breaking from two sides of the Co film. In laterally finite systems, their constrained geometry causes poor thermal stability of the skyrmion toward collapse at the boundary, which we show to be resolved by designing the high-DMI structure within an extended film with lower or no DMI. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Editor | |||
Language | Wos | 000404015500001 | Publication Date | 2017-06-23 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 48 | Open Access | |
Notes | This work was supported by the Research Foundation, Flanders (FWO-Vlaanderen) and Brazilian agency CNPq (Grants No. 442668/2014-7 and No. 140840/2016-8). | Approved | Most recent IF: 3.836 | ||
Call Number | CMT @ cmt @c:irua:144865 | Serial | 4704 | ||
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Author | Nicholas, R.J.; Sasaki, S.; Miura, N.; Peeters, F.M.; Shi, J.M.; Hai, G.Q.; Devreese, J.T.; Lawless, M.J.; Ashenford, D.E.; Lunn, B. | ||||
Title | Interband magnetooptical studies of resonant polaron coupling in CdTe/Cd1-xMnxTe quantum-wells | Type | A1 Journal article | ||
Year | 1994 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
Volume | 50 | Issue | 11 | Pages | 7596-7601 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems | ||||
Abstract | Magnetoreflectivity measurements of the 1s and 2s exciton energies in a CdTe/Cd1-xMnxTe superlattice have been made in magnetic fields up to 45 T, showing the resonant polaron coupling of electrons to LO phonons. Strong reflectivity features are seen for both the 1s and 2s excitons, which show a strong field-dependent spin splitting due to the dilute magnetic barriers. At B-z=0, the 2s exciton feature is observed lying 18 meV above the Is state, and is shifted upward in energy by the magnetic fields. No resonant behavior occurs when the 2s state passes through the LO-phonon energy of 21 meV, but at higher fields of around 20 T, the resonances for both spin states (sigma(+/-)) of the 2s exciton broaden and show a strong anticrossing behavior. These experiments are shown to be in excellent agreement with a theoretical treatment which includes the resonant polaron coupling of the electrons alone. Both experiment and theory demonstrate an extremely strong resonant splitting of the 2s exciton states of approximately 11 meV, which is over 50% of the LO-phonon energy. The dominance of single-particle polaron coupling is attributed to the relative sizes of the polaron (35 Angstrom A) and the exciton (50 Angstrom A) radius. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | A1994PJ43700045 | Publication Date | 2002-07-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0163-1829;1095-3795; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.736 | Times cited | 10 | Open Access | |
Notes | Approved | no | |||
Call Number | UA @ lucian @ c:irua:99837 | Serial | 1687 | ||
Permanent link to this record | |||||
Author | Singh, S.K.; Neek-Amal, M.; Costamagna, S.; Peeters, F.M. | ||||
Title | Rippling, buckling, and melting of single- and multilayer MoS2 | Type | A1 Journal article | ||
Year | 2015 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
Volume | 91 | Issue | 91 | Pages | 014101 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Large-scale atomistic simulations using the reactive empirical bond order force field approach is implemented to investigate thermal and mechanical properties of single-layer (SL) and multilayer (ML) molybdenum disulfide (MoS2). The amplitude of the intrinsic ripples of SL MoS2 are found to be smaller than those exhibited by graphene (GE). Furthermore, because of the van der Waals interaction between layers, the out-of-plane thermal fluctuations of ML MoS2 decreases rapidly with increasing number of layers. This trend is confirmed by the buckling transition due to uniaxial stress which occurs for a significantly larger applied tension as compared to graphene. For SL MoS2, the melting temperature is estimated to be 3700 K which occurs through dimerization followed by the formation of small molecules consisting of two to five atoms. When different types of vacancies are inserted in the SL MoS2 it results in a decrease of both the melting temperature as well as the stiffness. | ||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000347921300001 | Publication Date | 2015-01-05 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 1098-0121;1550-235X; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 40 | Open Access | |
Notes | ; This work is supported by the ESF-Eurographene project CONGRAN, the Flemish Science Foundation (FWO-VI), and the Methusalem Foundation of the Flemish Government. We acknowledge funding from the FWO (Belgium)-MINCyT (Argentina) collaborative research project. We would like to thanks Prof. Douglas E. Spearot [26] for giving us the implemented parameters of Mo-S in LAMMPS. ; | Approved | Most recent IF: 3.836; 2015 IF: 3.736 | ||
Call Number | c:irua:123834 | Serial | 2909 | ||
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Author | Leys, F.E.; March, N.H.; Angilella, G.G.N.; Lamoen, D. | ||||
Title | Self consistent nonlocal linear-response theory of a relativistic electron gas | Type | A1 Journal article | ||
Year | 2003 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
Volume | 67 | Issue | Pages | 113105 | |
Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000182035100005 | Publication Date | 2003-04-01 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0163-1829;1095-3795; | ISBN | Additional Links | UA library record; WoS full record; | |
Impact Factor | 3.836 | Times cited | Open Access | ||
Notes | Approved | Most recent IF: 3.836; 2003 IF: NA | |||
Call Number | UA @ lucian @ c:irua:45627 | Serial | 2973 | ||
Permanent link to this record | |||||
Author | Misko, V.R.; Fomin, V.M.; Devreese, J.T. | ||||
Title | Strong enhancement of superconductivity in a nanosized Pb bridge | Type | A1 Journal article | ||
Year | 2001 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
Volume | 64 | Issue | Pages | 014517,1-13 | |
Keywords | A1 Journal article; Electron Microscopy for Materials Science (EMAT); | ||||
Abstract | |||||
Address | |||||
Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000169711900093 | Publication Date | 2002-07-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0163-1829;1095-3795; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 28 | Open Access | |
Notes | Approved | Most recent IF: 3.836; 2001 IF: NA | |||
Call Number | UA @ lucian @ c:irua:34316 | Serial | 3181 | ||
Permanent link to this record | |||||
Author | Wang, Y.J.; Leem, Y.A.; McCombe, B.D.; Wu, X.G.; Peeters, F.M.; Jones, E.D.; Reno, J.R.; Lee, X.Y.; Jiang, H.W. | ||||
Title | Strong three-level resonant magnetopolaron effect due to the intersubband coupling in heavily modulation-doped GaAs/AlxGa1-xAs single quantum wells at high magnetic-fields | Type | A1 Journal article | ||
Year | 2001 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
Volume | 64 | Issue | 16 | Pages | 161303 |
Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
Abstract | Electron cyclotron resonance CR) measurements have been carried out in magnetic fields up to 32 T to study electron-phonon interaction in two heavily modulation-delta -doped GaAs/Al0.3Ga0.7As single-quantum-well samples. No measurable resonant magnetopolaron effects were observed in either sample in the region of the GaAs longitudinal optical (LO) phonons. However, when the CR frequency is above LO phonon frequency, omega (LO)=E-LO/(h) over bar, at high magnetic fields (B>27 T), electron CR exhibits a strong avoided-level-crossing splitting for both samples at frequencies close to (omega (LO)+ (E-2-E-1)1 (h) over bar, where E-2, and E-1 are the energies of the bottoms of the second and the first subbands, respectively. The energy separation between the two branches is large with the minimum separation of 40 cm(-1) occurring at around 30.5 T. A detailed theoretical analysis, which includes a self-consistent calculation of the band structure and the effects of electron-phonon interaction on the CR, shows that this type of splitting is due to a three-level resonance between the second Landau level of the first electron subband and the lowest Landau level of the second subband plus one GaAs LO phonon. The absence of occupation effects in the final states and weak screening or this three-level process yields large energy separation even in the presence of high electron densities. Excellent agreement between the theory and the experimental results is obtained. | ||||
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Corporate Author | Thesis | ||||
Publisher | Place of Publication | Lancaster, Pa | Editor | ||
Language | Wos | 000171866400009 | Publication Date | 2002-07-27 | |
Series Editor | Series Title | Abbreviated Series Title | |||
Series Volume | Series Issue | Edition | |||
ISSN | 0163-1829;1095-3795; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
Impact Factor | 3.836 | Times cited | 7 | Open Access | |
Notes | Approved | Most recent IF: 3.836; 2001 IF: NA | |||
Call Number | UA @ lucian @ c:irua:37278 | Serial | 3184 | ||
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