TY  - JOUR
AU  - Topalović, Dušan
AU  - Arsoski, Vladimir V.
AU  - Tadić, Milan Ž.
AU  - Peeters, Francois M.
PY  - 2020
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/9616
AB  - We investigate the electron states in double asymmetric HgTe / Cd x Hg 1 - x Te quantum wells grown along the [001] direction. The subbands are computed by means of the envelope function approximation applied to the eight-band Kane k ⋅ p model. The asymmetry of the confining potential of the double quantum wells results in a gap opening, which is absent in the symmetric system where it can only be induced by an applied electric field. The bandgap and the subbands are affected by spin-orbit coupling, which is a consequence of the asymmetry of the confining potential. The electron-like and hole-like states are mainly confined in different quantum wells, and the enhanced hybridization between them opens a spin-dependent hybridization gap at a finite in-plane wavevector. We show that both the ratio of the widths of the two quantum wells and the mole fraction of the C d x H g 1 - x Te barrier control both the energy gap between the hole-like states and the hybridization gap. The energy subbands are shown to exhibit inverted ordering, and therefore, a nontrivial topological phase could emerge in the system. © 2020 Author(s).
T2  - Journal of Applied Physics
T1  - Asymmetric versus symmetric HgTe / Cd x Hg 1 - X Te double quantum wells: Bandgap tuning without electric field
VL  - 128
IS  - 6
DO  - 10.1063/5.0016069
ER  - 

@article{
author = "Topalović, Dušan and Arsoski, Vladimir V. and Tadić, Milan Ž. and Peeters, Francois M.",
year = "2020",
abstract = "We investigate the electron states in double asymmetric HgTe / Cd x Hg 1 - x Te quantum wells grown along the [001] direction. The subbands are computed by means of the envelope function approximation applied to the eight-band Kane k ⋅ p model. The asymmetry of the confining potential of the double quantum wells results in a gap opening, which is absent in the symmetric system where it can only be induced by an applied electric field. The bandgap and the subbands are affected by spin-orbit coupling, which is a consequence of the asymmetry of the confining potential. The electron-like and hole-like states are mainly confined in different quantum wells, and the enhanced hybridization between them opens a spin-dependent hybridization gap at a finite in-plane wavevector. We show that both the ratio of the widths of the two quantum wells and the mole fraction of the C d x H g 1 - x Te barrier control both the energy gap between the hole-like states and the hybridization gap. The energy subbands are shown to exhibit inverted ordering, and therefore, a nontrivial topological phase could emerge in the system. © 2020 Author(s).",
journal = "Journal of Applied Physics",
title = "Asymmetric versus symmetric HgTe / Cd x Hg 1 - X Te double quantum wells: Bandgap tuning without electric field",
volume = "128",
number = "6",
doi = "10.1063/5.0016069"
}

Topalović, D., Arsoski, V. V., Tadić, M. Ž.,& Peeters, F. M.. (2020). Asymmetric versus symmetric HgTe / Cd x Hg 1 - X Te double quantum wells: Bandgap tuning without electric field. in Journal of Applied Physics, 128(6).
https://doi.org/10.1063/5.0016069

Topalović D, Arsoski VV, Tadić MŽ, Peeters FM. Asymmetric versus symmetric HgTe / Cd x Hg 1 - X Te double quantum wells: Bandgap tuning without electric field. in Journal of Applied Physics. 2020;128(6).
doi:10.1063/5.0016069 .

Topalović, Dušan, Arsoski, Vladimir V., Tadić, Milan Ž., Peeters, Francois M., "Asymmetric versus symmetric HgTe / Cd x Hg 1 - X Te double quantum wells: Bandgap tuning without electric field" in Journal of Applied Physics, 128, no. 6 (2020),
https://doi.org/10.1063/5.0016069 . .

TY  - JOUR
AU  - Topalović, Dušan
AU  - Arsoski, Vladimir
AU  - Tadić, Milan Ž.
AU  - Peeters, François M.
PY  - 2019
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/8534
AB  - We investigate the electron states and optical absorption in square- and hexagonal-shaped two-dimensional (2D) HgTe quantum dots and quantum rings in the presence of a perpendicular magnetic field. The electronic structure is modeled by means of the sp3d5s∗ tight-binding method within the nearest-neighbor approximation. Both bulklike and edge states appear in the energy spectrum. The bulklike states in quantum rings exhibit Aharonov-Bohm oscillations in magnetic field, whereas no such oscillations are found in quantum dots, which is ascribed to the different topology of the two systems. When magnetic field varies, all the edge states in square quantum dots appear as quasibands composed of almost fully flat levels, whereas some edge states in quantum rings are found to oscillate with magnetic field. However, the edge states in hexagonal quantum dots are localized like in rings. The absorption spectra of all the structures consist of numerous absorption lines, which substantially overlap even for small line broadening. The absorption lines in the infrared are found to originate from transitions between edge states. It is shown that the magnetic field can be used to efficiently tune the optical absorption of HgTe 2D quantum dot and quantum ring systems. © 2019 American Physical Society.
T2  - Physical Review B
T1  - Confined electron states in two-dimensional HgTe in magnetic field: Quantum dot versus quantum ring behavior
VL  - 100
IS  - 12
SP  - 125304
DO  - 10.1103/PhysRevB.100.125304
ER  - 

@article{
author = "Topalović, Dušan and Arsoski, Vladimir and Tadić, Milan Ž. and Peeters, François M.",
year = "2019",
abstract = "We investigate the electron states and optical absorption in square- and hexagonal-shaped two-dimensional (2D) HgTe quantum dots and quantum rings in the presence of a perpendicular magnetic field. The electronic structure is modeled by means of the sp3d5s∗ tight-binding method within the nearest-neighbor approximation. Both bulklike and edge states appear in the energy spectrum. The bulklike states in quantum rings exhibit Aharonov-Bohm oscillations in magnetic field, whereas no such oscillations are found in quantum dots, which is ascribed to the different topology of the two systems. When magnetic field varies, all the edge states in square quantum dots appear as quasibands composed of almost fully flat levels, whereas some edge states in quantum rings are found to oscillate with magnetic field. However, the edge states in hexagonal quantum dots are localized like in rings. The absorption spectra of all the structures consist of numerous absorption lines, which substantially overlap even for small line broadening. The absorption lines in the infrared are found to originate from transitions between edge states. It is shown that the magnetic field can be used to efficiently tune the optical absorption of HgTe 2D quantum dot and quantum ring systems. © 2019 American Physical Society.",
journal = "Physical Review B",
title = "Confined electron states in two-dimensional HgTe in magnetic field: Quantum dot versus quantum ring behavior",
volume = "100",
number = "12",
pages = "125304",
doi = "10.1103/PhysRevB.100.125304"
}

Topalović, D., Arsoski, V., Tadić, M. Ž.,& Peeters, F. M.. (2019). Confined electron states in two-dimensional HgTe in magnetic field: Quantum dot versus quantum ring behavior. in Physical Review B, 100(12), 125304.
https://doi.org/10.1103/PhysRevB.100.125304

Topalović D, Arsoski V, Tadić MŽ, Peeters FM. Confined electron states in two-dimensional HgTe in magnetic field: Quantum dot versus quantum ring behavior. in Physical Review B. 2019;100(12):125304.
doi:10.1103/PhysRevB.100.125304 .

Topalović, Dušan, Arsoski, Vladimir, Tadić, Milan Ž., Peeters, François M., "Confined electron states in two-dimensional HgTe in magnetic field: Quantum dot versus quantum ring behavior" in Physical Review B, 100, no. 12 (2019):125304,
https://doi.org/10.1103/PhysRevB.100.125304 . .