|
Records |
|
Author |
Varjovi, M.J.; Yagmurcukardes, M.; Peeters, F.M.; Durgun, E. |
|
Title |
Janus two-dimensional transition metal dichalcogenide oxides: First-principles investigation of WXO monolayers with X = S, Se, and Te |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
103 |
Issue |
19 |
Pages |
195438 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
Structural symmetry breaking in two-dimensional materials can lead to superior physical properties and introduce an additional degree of piezoelectricity. In the present paper, we propose three structural phases (1H, 1T, and 1T') of Janus WXO (X = S, Se, and Te) monolayers and investigate their vibrational, thermal, elastic, piezoelectric, and electronic properties by using first-principles methods. Phonon spectra analysis reveals that while the 1H phase is dynamically stable, the 1T phase exhibits imaginary frequencies and transforms to the distorted 1T' phase. Ab initio molecular dynamics simulations confirm that 1H- and 1T'-WXO monolayers are thermally stable even at high temperatures without any significant structural deformations. Different from binary systems, additional Raman active modes appear upon the formation of Janus monolayers. Although the mechanical properties of 1H-WXO are found to be isotropic, they are orientation dependent for 1T'-WXO. It is also shown that 1H-WXO monolayers are indirect band-gap semiconductors and the band gap narrows down the chalcogen group. Except 1T'-WSO, 1T'-WXO monolayers have a narrow band gap correlated with the Peierls distortion. The effect of spin-orbit coupling on the band structure is also examined for both phases and the alteration in the band gap is estimated. The versatile mechanical and electronic properties of Janus WXO monolayers together with their large piezoelectric response imply that these systems are interesting for several nanoelectronic applications. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000655902600004 |
Publication Date |
2021-05-26 |
|
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 |
3.836 |
Times cited |
78 |
Open Access |
Not_Open_Access |
|
Notes |
|
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ admin @ c:irua:179050 |
Serial |
7000 |
Permanent link to this record |
|
|
|
|
Author |
Yagmurcukardes, M.; Mogulkoc, Y.; Akgenc, B.; Mogulkoc, A.; Peeters, F.M. |
|
Title |
Prediction of monoclinic single-layer Janus Ga₂ Te X (X = S and Se) : strong in-plane anisotropy |
Type |
A1 Journal article |
|
Year |
2021 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
104 |
Issue |
4 |
Pages |
045425 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
By using density functional theory (DFT) based first-principles calculations, electronic, vibrational, piezo-electric, and optical properties of monoclinic Janus single-layer Ga2TeX (X = S or Se) are investigated. The dynamical, mechanical, and thermal stability of the proposed Janus single layers are verified by means of phonon bands, stiffness tensor, and quantum molecular dynamics simulations. The calculated vibrational spectrum reveals the either pure or coupled optical phonon branches arising from Ga-Te and Ga-X atoms. In addition to the in-plane anisotropy, single-layer Janus Ga2TeX exhibits additional out-of-plane asymmetry, which leads to important consequences for its electronic and optical properties. Electronic band dispersions indicate the direct band-gap semiconducting nature of the constructed Janus structures with energy band gaps falling into visible spectrum. Moreover, while orientation-dependent linear-elastic properties of Janus single layers indicate their strong anisotropy, the calculated in-plane stiffness values reveal the ultrasoft nature of the structures. In addition, predicted piezoelectric coefficients show that while there is a strong in-plane anisotropy between piezoelectric constants along armchair (AC) and zigzag (ZZ) directions, there exists a tiny polarization along the out-of-plane direction as a result of the formation of Janus structure. The optical response to electromagnetic radiation has been also analyzed through density functional theory by considering the independent-particle approximation. Finally, the optical spectra of Janus Ga2TeX structures is investigated and it showed a shift from the ultraviolet region to the visible region. The fact that the spectrum is between these regions will allow it to be used in solar energy and many nanoelectronics applications. The predicted monoclinic single-layer Janus Ga2TeX are relevant for promising applications in optoelectronics, optical dichroism, and anisotropic nanoelasticity. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000678811100007 |
Publication Date |
2021-07-26 |
|
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 |
3.836 |
Times cited |
14 |
Open Access |
Not_Open_Access |
|
Notes |
|
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ admin @ c:irua:180404 |
Serial |
7013 |
Permanent link to this record |
|
|
|
|
Author |
Man, L.F.; Xu, W.; Xiao, Y.M.; Wen, H.; Ding, L.; Van Duppen, B.; Peeters, F.M. |
|
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 |
|
Volume |
104 |
Issue |
12 |
Pages |
125420 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
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. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000704419300004 |
Publication Date |
2021-09-15 |
|
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 |
3.836 |
Times cited |
4 |
Open Access |
OpenAccess |
|
Notes |
|
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ admin @ c:irua:182518 |
Serial |
7029 |
Permanent link to this record |
|
|
|
|
Author |
Zhang, H.Y.; Xiao, Y.M.; N. Li, Q.; Ding, L.; Van Duppen, B.; Xu, W.; Peeters, F.M. |
|
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 |
|
Volume |
105 |
Issue |
11 |
Pages |
115423-115429 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
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. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000802810700002 |
Publication Date |
2022-03-22 |
|
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 |
3.7 |
Times cited |
3 |
Open Access |
OpenAccess |
|
Notes |
|
Approved |
Most recent IF: 3.7 |
|
Call Number |
UA @ admin @ c:irua:188660 |
Serial |
7125 |
Permanent link to this record |
|
|
|
|
Author |
Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V. |
|
Title |
Controlling the hybridization gap and transport in a thin-film topological insulator : effect of strain, and electric and magnetic field |
Type |
A1 Journal article |
|
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
106 |
Issue |
3 |
Pages |
035119-7 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
In a thin-film topological insulator (TI), the edge states on two surfaces may couple by quantum tunneling, opening a gap known as the hybridization gap. Controlling the hybridization gap and transport has a variety of potential uses in photodetection and energy-harvesting applications. In this paper, we report the effect of strain, and electric and magnetic field, on the hybridization gap and transport in a thin Bi2Se3 film, investigated within the tight-binding theoretical framework. We demonstrate that vertical compression decreases the hybridization gap, as does tensile in-plane strain. Applying an electric field breaks the inversion symmetry and leads to a Rashba-like spin splitting proportional to the electric field, hence closing and reopening the gap. The influence of a magnetic field on thin-film TI is also discussed, starting from the role of an out-of-plane magnetic field on quantum Hall states. We further demonstrate that the hybridization gap can be controlled by an in-plane magnetic field, and that by applying a sufficiently strong field a quantum phase transition from an insulator to a semimetal can be achieved. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000832277500001 |
Publication Date |
2022-07-13 |
|
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 |
7 |
Open Access |
Not_Open_Access |
|
Notes |
|
Approved |
Most recent IF: 3.7 |
|
Call Number |
UA @ admin @ c:irua:189515 |
Serial |
7140 |
Permanent link to this record |
|
|
|
|
Author |
Mirzakhani, M.; da Costa, D.R.; Peeters, F.M. |
|
Title |
Isolated and hybrid bilayer graphene quantum rings |
Type |
A1 Journal article |
|
Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
105 |
Issue |
11 |
Pages |
115430-11 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
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. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000801209300006 |
Publication Date |
2022-03-28 |
|
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 |
4 |
Open Access |
OpenAccess |
|
Notes |
|
Approved |
Most recent IF: 3.7 |
|
Call Number |
UA @ admin @ c:irua:188703 |
Serial |
7175 |
Permanent link to this record |
|
|
|
|
Author |
Cunha, S.M.; da Costa, D.R.; Pereira, J.M., Jr.; Costa Filho, R.N.; Van Duppen, B.; Peeters, F.M. |
|
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 |
|
Volume |
105 |
Issue |
16 |
Pages |
165402-165414 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
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. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000805195200001 |
Publication Date |
2022-04-01 |
|
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 |
|
Call Number |
UA @ admin @ c:irua:188614 |
Serial |
7222 |
Permanent link to this record |
|
|
|
|
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. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
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 |
Permanent link to this record |
|
|
|
|
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. |
|
Address |
|
|
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 |
Permanent link to this record |
|
|
|
|
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. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
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 |
Permanent link to this record |
|
|
|
|
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. |
|
Address |
|
|
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 |
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. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
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 |
Permanent link to this record |
|
|
|
|
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. |
|
Address |
|
|
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 |
Permanent link to this record |
|
|
|
|
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 |
Permanent link to this record |
|
|
|
|
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 |
Permanent link to this record |
|
|
|
|
Author |
Bacaksiz, C.; Cahangirov, S.; Rubio, A.; Senger, R.T.; Peeters, F.M.; Sahin, H. |
|
Title |
Bilayer SnS2 : tunable stacking sequence by charging and loading pressure |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
125403 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
Employing density functional theory-based methods, we investigate monolayer and bilayer structures of hexagonal SnS2, which is a recently synthesized monolayer metal dichalcogenide. Comparison of the 1H and 1T phases of monolayer SnS2 confirms the ground state to be the 1T phase. In its bilayer structure we examine different stacking configurations of the two layers. It is found that the interlayer coupling in bilayer SnS2 is weaker than that of typical transition-metal dichalcogenides so that alternative stacking orders have similar structural parameters and they are separated with low energy barriers. A possible signature of the stacking order in the SnS2 bilayer has been sought in the calculated absorbance and reflectivity spectra. We also study the effects of the external electric field, charging, and loading pressure on the characteristic properties of bilayer SnS2. It is found that (i) the electric field increases the coupling between the layers at its preferred stacking order, so the barrier height increases, (ii) the bang gap value can be tuned by the external E field and under sufficient E field, the bilayer SnS2 can become a semimetal, (iii) the most favorable stacking order can be switched by charging, and (iv) a loading pressure exceeding 3 GPa changes the stacking order. The E-field tunable band gap and easily tunable stacking sequence of SnS2 layers make this 2D crystal structure a good candidate for field effect transistor and nanoscale lubricant applications. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000371405000005 |
Publication Date |
2016-03-03 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
38 |
Open Access |
|
|
Notes |
; The calculations were performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). C.B., H.S., and R.T.S. acknowledge support from TUBITAK Project No. 114F397. H.S. is supported by an FWO Pegasus Marie Curie Fellowship. S.C. and A.R. acknowledge financial support from the Marie Curie grant FP7-PEOPLE-2013-IEF Project No. 628876, the European Research Council (ERC-2010-AdG-267374), and Spanish grant Grupos Consolidados (IT578-13). S.C. acknowledges support from the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 115F388. ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:132345 |
Serial |
4144 |
Permanent link to this record |
|
|
|
|
Author |
Van der Donck, M.; Peeters, F.M.; Van Duppen, B. |
|
Title |
Comment on “Creating in-plane pseudomagnetic fields in excess of 1000 T by misoriented stacking in a graphene bilayer” |
Type |
Editorial |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
247401 |
|
Keywords |
Editorial; Condensed Matter Theory (CMT) |
|
Abstract |
In a recent paper [Phys. Rev. B 89, 125418 (2014)], the authors argue that it is possible to map the electronic properties of twisted bilayer graphene to those of bilayer graphene in an in-plane magnetic field. However, their description of the low-energy dynamics of twisted bilayer graphene is restricted to the extended zone scheme and therefore neglects the effects of the superperiodic structure. If the energy spectrum is studied in the supercell Brillouin zone, we find that the comparison with an in-plane magnetic field fails because (i) the energy spectra of the two situations exhibit different symmetries and (ii) the low-energy spectra are very different. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
Amer physical soc |
Place of Publication |
College pk |
Editor |
|
|
Language |
|
Wos |
000377802200009 |
Publication Date |
2016-06-14 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
|
|
Notes |
; ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:134601 |
Serial |
4151 |
Permanent link to this record |
|
|
|
|
Author |
Mirzakhani, M.; Zarenia, M.; Ketabi, S.A.; da Costa, D.R.; Peeters, F.M. |
|
Title |
Energy levels of hybrid monolayer-bilayer graphene quantum dots |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
165410 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
Often real samples of graphene consist of islands of both monolayer and bilayer graphene. Bound states in such hybrid quantum dots are investigated for (i) a circular single-layer graphene quantum dot surrounded by an infinite bilayer graphene sheet and (ii) a circular bilayer graphene quantum dot surrounded by an infinite single-layer graphene. Using the continuum model and applying zigzag boundary conditions at the single-layer-bilayer graphene interface, we obtain analytical results for the energy levels and the corresponding wave spinors. Their dependence on perpendicular magnetic and electric fields are studied for both types of quantum dots. The energy levels exhibit characteristics of interface states, and we find anticrossings and closing of the energy gap in the presence of a bias potential. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000373572700004 |
Publication Date |
2016-04-09 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
26 |
Open Access |
|
|
Notes |
; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO)-CNPq project between Flanders and Brazil and the Brazilian Science Without Borders program. ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:133261 |
Serial |
4174 |
Permanent link to this record |
|
|
|
|
Author |
da Costa; Zarenia, M.; Chaves, A.; Pereira, J.M., Jr.; Farias, G.A.; Peeters, F.M. |
|
Title |
Hexagonal-shaped monolayer-bilayer quantum disks in graphene : a tight-binding approach |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
94 |
Issue |
94 |
Pages |
035415 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
Using the tight-binding approach, we investigate confined states in two different hybrid monolayer-bilayer systems: (i) a hexagonal monolayer area surrounded by bilayer graphene in the presence of a perpendicularly applied electric field and (ii) a hexagonal bilayer graphene dot surrounded by monolayer graphene. The dependence of the energy levels on dot size and external magnetic field is calculated. We find that the energy spectrum for quantum dots with zigzag edges consists of states inside the gap which range from dot-localized states, edge states, to mixed states coexisting together, whereas for dots with armchair edges, only dot-localized states are observed. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000379502200008 |
Publication Date |
2016-07-11 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
11 |
Open Access |
|
|
Notes |
; This work was financially supported by CNPq, under contract NanoBioEstruturas No. 555183/2005-0, PRONEX/FUNCAP, CAPES Foundation, under the process No. BEX 7178/13-1, the Flemish Science Foundation (FWO-Vl), the Bilateral programme between CNPq and FWO-Vl, the Brazilian Program Science Without Borders (CsF), and the Lemann Foundation. ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:134947 |
Serial |
4190 |
Permanent link to this record |
|
|
|
|
Author |
Ghorbanfekr-Kalashami, H.; Neek-Amal, M.; Peeters, F.M. |
|
Title |
N-doped graphene : polarization effects and structural properties |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
174112 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
The structural and mechanical properties of N-doped graphene (NG) are investigated using reactive force field (ReaxFF) potentials in large-scale molecular dynamics simulations. We found that ripples, which are induced by the dopants, change the roughness of NG, which depends on the number of dopants and their local arrangement. For any doping ratio N/C, the NG becomes ferroelectric with a net dipole moment. The formation energy increases nonlinearly with N/C ratio, while the Young's modulus, tensile strength, and intrinsic strain decrease with the number of dopants. Our results for the structural deformation and the thermoelectricity of the NG sheet are in good agreement with recent experiments and ab initio calculations. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000376245900002 |
Publication Date |
2016-05-20 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
15 |
Open Access |
|
|
Notes |
; This work was supported by the ESF-Eurographene project CONGRAN, and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:134148 |
Serial |
4212 |
Permanent link to this record |
|
|
|
|
Author |
Walter, A.L.; Sahin, H.; Kang, J.; Jeon, K.J.; Bostwick, A.; Horzum, S.; Moreschini, L.; Chang, Y.J.; Peeters, F.M.; Horn, K.; Rotenberg, E.; |
|
Title |
New family of graphene-based organic semiconductors : an investigation of photon-induced electronic structure manipulation in half-fluorinated graphene |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
075439 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
The application of graphene to electronic and optoelectronic devices is limited by the absence of reliable semiconducting variants of this material. A promising candidate in this respect is graphene oxide, with a band gap on the order of similar to 5 eV, however, this has a finite density of states at the Fermi level. Here, we examine the electronic structure of three variants of half-fluorinated carbon on Sic(0001), i.e., the (6 root 3 x 6 root 3) R30 degrees C/SiC “buffer layer,” graphene on this (6 root 3 x 6 root 3) R30 degrees C/SiC buffer layer, and graphene decoupled from the SiC substrate by hydrogen intercalation. Using angle-resolved photoemission, core level photoemission, and x-ray absorption, we show that the electronic, chemical, and physical structure of all three variants is remarkably similar, exhibiting a large band gap and a vanishing density of states at the Fermi level. These results are explained in terms of first-principles calculations. This material thus appears very suitable for applications, even more so since it is prepared on a processing-friendly substrate. We also investigate two separate UV photon-induced modifications of the electronic structure that transform the insulating samples (6.2-eV band gap) into semiconducting (similar to 2.5-eV band gap) and metallic regions, respectively. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000371398000007 |
Publication Date |
2016-02-29 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
5 |
Open Access |
|
|
Notes |
; The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under Contract No. DE-AC02-05CH11231. Work in Erlangen was supported by the DFG through SPP 1459 “Graphene” and SFB 953 “Synthetic Carbon Allotropes” and by the ESF through the EURO-Graphene project GraphicRF. A.L.W. acknowledges support from the Max-Planck-Gesellschaft, the Donostia International Physics Centre, and the Centro de Fisica de Materiales in San Sebastian, Spain, and Brookhaven National Laboratory under US Department of Energy, Office of Science, Office of Basic Energy Sciences, Contract No. DE-SC0012704. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus-Long Marie Curie Fellowship, and J.K. by a FWO Pegasus-Short Marie Curie Fellowship. Y.J.C. acknowledges support from the National Research Foundation of Korea under Grant No. NRF-2014R1A1A1002868. The authors gratefully acknowledge the work of T. Seyller's group at the Institut fur Physik, Technische Universitat Chemnitz, Germany for providing the samples. ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:132352 |
Serial |
4213 |
Permanent link to this record |
|
|
|
|
Author |
Torun, E.; Sahin, H.; Peeters, F.M. |
|
Title |
Optical properties of GaS-Ca(OH)2 bilayer heterostructure |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
075111 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
Finding novel atomically thin heterostructures and understanding their characteristic properties are critical for developing better nanoscale optoelectronic devices. In this study, we investigate the electronic and optical properties of a GaS-Ca(OH)(2) heterostructure using first-principle calculations. The band gap of the GaS-Ca(OH)(2) heterostructure is significantly reduced when compared to those of the isolated constituent layers. Our calculations showthat the GaS-Ca(OH)(2) heterostructure is a type-II heterojunction which can be used to separate photoinduced charge carriers where electrons are localized in GaS and holes in the Ca(OH)(2) layer. This leads to spatially indirect excitons which are important for solar energy and optoelectronic applications due to their long lifetime. By solving the Bethe-Salpeter equation on top of a single shot GW calculation (G(0)W(0)), the dielectric function and optical oscillator strength of the constituent monolayers and the heterostructure are obtained. The oscillator strength of the optical transition for the GaS monolayer is an order of magnitude larger than the Ca(OH)(2) monolayer. We also found that the calculated optical spectra of different stacking types of the heterostructure show dissimilarities, although their electronic structures are rather similar. This prediction can be used to determine the stacking type of ultrathin heterostructures. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000369401000001 |
Publication Date |
2016-02-06 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
18 |
Open Access |
|
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus long Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:131614 |
Serial |
4220 |
Permanent link to this record |
|
|
|
|
Author |
Zhao, H.J.; Wu, W.; Zhou, W.; Shi, Z.X.; Misko, V.R.; Peeters, F.M. |
|
Title |
Reentrant dynamics of driven pancake vortices in layered superconductors |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
94 |
Issue |
94 |
Pages |
024514 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
The dynamics of driven pancake vortices in layered superconductors is studied using molecular-dynamics simulations. We found that, with increasing driving force, for strong interlayer coupling, the preexisted vortex lines either directly depin or first transform to two-dimensional (2D) pinned states before they are depinned, depending on the pinning strength. In a narrow region of pinning strengths, we found an interesting repinning process, which results in a negative differential resistance. For weak interlayer coupling, individually pinned pancake vortices first form disordered 2D flow and then transform to ordered three-dimensional (3D) flow with increasing driving force. However, for extremely strong pinning, the random pinning-induced thermal-like Langevin forces melt 3D vortex lines, which results in a persistent 2D flow in the fast-sliding regime. In the intermediate regime, the peak effect is found: With increasing driving force, the moving pancake vortices first crystallize to moving 3D vortex lines, and then these 3D vortex lines are melted, leading to the appearance of a reentrant 2D flow state. Our results are summarized in a dynamical phase diagram. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000380097800006 |
Publication Date |
2016-07-18 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
3 |
Open Access |
|
|
Notes |
; We acknowledge useful discussions with C. Olson Reichhardt. This work was supported by the Natural Science Foundation of Jiangsu Province (Grant No. BK20150595), National Natural Science Foundation of China (Grants No. NSFC-U1432135 and No. 11611140101). V.R.M. acknowledges support from the “Odysseus” program of the Flemish Government and Flemish Science Foundation (FWO-Vl), the FWO-Vl, and the Research Fund of the University of Antwerp. ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:134943 |
Serial |
4238 |
Permanent link to this record |
|
|
|
|
Author |
Missault, N.; Vasilopoulos, P.; Peeters, F.M.; Van Duppen, B. |
|
Title |
Spin- and valley-dependent miniband structure and transport in silicene superlattices |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
125425 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
We investigate silicene superlattices in the presence of a tunable barrier potential U, an exchange field M, and a perpendicular electric field E-z. The resulting miniband structure depends on the spin and valley indices and on the fields M and E-z. These fields determine the minigaps and also affect the additional Dirac points brought about by the periodic potential U. In addition, we consider diffusive transport and assess its dependence on the spin and valley indices as well as on temperature. The corresponding spin and valley polarizations strongly depend on the potential U and can be made almost 100% at very low temperatures at particular values of the Fermi energy. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000372715800009 |
Publication Date |
2016-03-21 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
49 |
Open Access |
|
|
Notes |
; This work was supported by the Canadian NSERC Grant No. OGP0121756 (P.V.), and by the Flemish Science Foundation FWO-Vl) with the “Odysseus” Program (N. M.) and with a PhD research grant (B.V.D.). ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:133194 |
Serial |
4246 |
Permanent link to this record |
|
|
|
|
Author |
Chaves, A.; Mayers, M.Z.; Peeters, F.M.; Reichman, D.R. |
|
Title |
Theoretical investigation of electron-hole complexes in anisotropic two-dimensional materials |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
115314 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
Trions and biexcitons in anisotropic two-dimensional materials are investigated within an effective mass theory. Explicit results are obtained for phosphorene and arsenene, materials that share features such as a direct quasiparticle gap and anisotropic conduction and valence bands. Trions are predicted to have remarkably high binding energies and an elongated electron-hole structure with a preference for alignment along the armchair direction, where the effective masses are lower. We find that biexciton binding energies are also notably large, especially for monolayer phosphorene, where they are found to be twice as large as those for typical monolayer transition metal dichalcogenides. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000372715700001 |
Publication Date |
2016-03-25 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
33 |
Open Access |
|
|
Notes |
; This work has been financially supported by CNPq, through the PRONEX/FUNCAP and Science Without Borders programs, the FWO-CNPq bilateral program between Brazil and Flanders, and the Lemann Foundation. M.Z.M. is supported by a fellowship from the National Science Foundation, under Grant No. DGE-11-44155. ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:133191 |
Serial |
4262 |
Permanent link to this record |
|
|
|
|
Author |
Van der Donck, M.; Peeters, F.M.; Van Duppen, B. |
|
Title |
Transport properties of bilayer graphene in a strong in-plane magnetic field |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
115423 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
A strong in-plane magnetic field drastically alters the low-energy spectrum of bilayer graphene by separating the parabolic energy dispersion into two linear Dirac cones. The effect of this dramatic change on the transport properties strongly depends on the orientation of the in-plane magnetic field with respect to the propagation direction of the charge carriers and the angle at which they impinge on the electrostatic potentials. For magnetic fields oriented parallel to the potential boundaries an additional propagating mode that results from the splitting into Dirac cones enhances the transmission probability for charge carriers tunneling through the potentials and increases the corresponding conductance. Our results show that the chiral suppression of transmission at normal incidence, reminiscent of bilayer graphene's 2 pi Berry phase, is turned into a chiral enhancement when the magnetic field increases, thus indicating a transition from a bilayer to a monolayer-like system at normal incidence. Further, we find that the typical transmission resonances stemming from confinement in a potential barrier are shifted to higher energy and are eventually transformed into antiresonances with increasing magnetic field. For magnetic fields oriented perpendicular to the potential boundaries we find a very pronounced transition from a bilayer system to two separated monolayer-like systems with Klein tunneling emerging at certain incident angles symmetric around 0, which also leaves a signature in the conductance. For both orientations of the magnetic field, the transmission probability is still correctly described by pseudospin conservation. Finally, to motivate the large in-plane magnetic field, we show that its energy spectrum can be mimicked by specific lattice deformations such as a relative shift of one of the layers. With this equivalence we introduce the notion of an in-plane pseudomagnetic field. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000372409900006 |
Publication Date |
2016-03-21 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
11 |
Open Access |
|
|
Notes |
; This work was supported by Fonds Wetenschappelijk Onderzoek (FWO-Vl) through an aspirant research grant to M.V.D.D. and B.V.D. ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:133197 |
Serial |
4267 |
Permanent link to this record |
|
|
|
|
Author |
Grujić, M.M.; Ezawa, M.; Tadic, M.Z.; Peeters, F.M. |
|
Title |
Tunable skewed edges in puckered structures |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
245413 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
We propose a type of edges arising due to the anisotropy inherent in the puckered structure of a honeycomb system such as in phosphorene. Skewed-zigzag and skewed-armchair nanoribbons are semiconducting and metallic, respectively, in contrast to their normal edge counterparts. Their band structures are tunable, and a metal-insulator transition is induced by an electric field. We predict a field-effect transistor based on the edge states in skewed-armchair nanoribbons, where the edge state is gapped by applying arbitrary small electric field E-z. A topological argument is presented, revealing the condition for the emergence of such edge states. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000377802700010 |
Publication Date |
2016-06-16 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
|
|
Notes |
; This work was supported by the Serbian Ministry of Education, Science and Technological Development, and the Flemish Science Foundation (FWO-Vl). M.E. is thankful for the support by the Grants-in-Aid for Scientific Research from MEXT KAKENHI (Grants No. 25400317 and No. 15H05854). ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:134599 |
Serial |
4268 |
Permanent link to this record |
|
|
|
|
Author |
Fernández Becerra, V.; Sardella, E.; Peeters, F.M.; Milošević, M.V. |
|
Title |
Vortical versus skyrmionic states in mesoscopic p-wave superconductors |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
93 |
Issue |
93 |
Pages |
014518 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
We investigate the superconducting states that arise as a consequence of mesoscopic confinement and a multicomponent order parameter in the Ginzburg-Landau model for p-wave superconductivity. Conventional vortices, but also half-quantum vortices and skyrmions, are found as the applied magnetic field and the anisotropy parameters of the Fermi surface are varied. The solutions are well differentiated by a topological charge that for skyrmions is given by the Hopf invariant and for vortices by the circulation of the superconducting velocity. We revealed several unique states combining vortices and skyrmions, their possible reconfiguration with varied magnetic field, as well as temporal and field-induced transitions between vortical and skyrmionic states. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000369217400004 |
Publication Date |
2016-01-29 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
28 |
Open Access |
|
|
Notes |
; This work was supported by the Research Foundation – Flanders (FWO). E.S. acknowledges support from the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP). ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:131581 |
Serial |
4275 |
Permanent link to this record |
|
|
|
|
Author |
Sisakht, E.T.; Fazileh, F.; Zare, M.H.; Zarenia, M.; Peeters, F.M. |
|
Title |
Strain-induced topological phase transition in phosphorene and in phosphorene nanoribbons |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
94 |
Issue |
94 |
Pages |
085417 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
Using the tight-binding (TB) approximation with inclusion of the spin-orbit interaction, we predict a topological phase transition in the electronic band structure of phosphorene in the presence of axial strains. We derive a low-energy TB Hamiltonian that includes the spin-orbit interaction for bulk phosphorene. Applying a compressive biaxial in-plane strain and perpendicular tensile strain in ranges where the structure is still stable leads to a topological phase transition. We also examine the influence of strain on zigzag phosphorene nanoribbons (zPNRs) and the formation of the corresponding protected edge states when the system is in the topological phase. For zPNRs up to a width of 100 nm the energy gap is at least three orders of magnitude larger than the thermal energy at room temperature. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000381600800004 |
Publication Date |
2016-08-18 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
76 |
Open Access |
|
|
Notes |
; This work was supported by Ministry of Science, Research and Technology, Iran. M.Z. acknowledges support as a postdoctoral fellow of the Flemish Research Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:135643 |
Serial |
4309 |
Permanent link to this record |
|
|
|
|
Author |
Mirzakhani, M.; Zarenia, M.; da Costa, D.R.; Ketabi, S.A.; Peeters, F.M. |
|
Title |
Energy levels of ABC-stacked trilayer graphene quantum dots with infinite-mass boundary conditions |
Type |
A1 Journal article |
|
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
|
Volume |
94 |
Issue |
94 |
Pages |
165423 |
|
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
Abstract |
Using the continuum model, we investigate the confined states and the corresponding wave functions of ABC-stacked trilayer graphene (TLG) quantum dots (QDs). First, a general infinite-mass boundary condition is derived and applied to calculate the electron and hole energy levels of a circular QD in both the absence and presence of a perpendicular magnetic field. Our analytical results for the energy spectra agree with those obtained by using the tight-binding model, where a TLG QD is surrounded by a staggered potential. Our findings show that (i) the energy spectrum exhibits intervalley symmetry E-K(e)(m) = -E-K'(h)(m) for the electron (e) and hole (h) states, where m is the angular momentum quantum number, (ii) the zero-energy Landau level (LL) is formed by the magnetic states with m <= 0 for both Dirac valleys, that is different from monolayer and bilayer graphene QD with infinite-mass potential in which only one of the cones contributes, and (iii) groups of three quantum Hall edge states in the tight-binding magnetic spectrum approach the zero LL, which results from the layer symmetry in TLG QDs. |
|
Address |
|
|
Corporate Author |
|
Thesis |
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
Language |
|
Wos |
000386168000011 |
Publication Date |
2016-10-19 |
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
ISSN |
2469-9950;2469-9969; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
Impact Factor |
3.836 |
Times cited |
9 |
Open Access |
|
|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl), the Brazilian Council for Research (CNPq), the Science without Borders program, PRONEX/FUNCAP, and CAPES foundation. ; |
Approved |
Most recent IF: 3.836 |
|
Call Number |
UA @ lucian @ c:irua:138174 |
Serial |
4353 |
Permanent link to this record |