PSJD - Yadda

1

Analysis of the Quantum Spin Hall and Quantum Anomalous Hall Effects in a Two-Dimensional Decorated Lattice Using Entanglement Spectrum

100%

Piekarska A., Potasz P., Wójs A.

Acta Physica Polonica A

|

2016

|

vol. 129

|

issue 1a

A-87-A-89

EN

We study topological properties of a two-dimensional decorated lattice using entanglement spectrum and trace index. Using these measures, we distinguish various phases of the system predicted recently, including the quantum spin Hall effect and quantum anomalous Hall effect. The topologically trivial and non-trivial phases are identified, with assignment of a Chern number to each of the bands.

2

Study of Spin-Orbit Coupling Effect on Bismuth (111) Bilayer

100%

Bieniek M., Woźniak T., Potasz P.

Acta Physica Polonica A

|

2016

|

vol. 130

|

issue 2

609-612

EN

Band inversion process in Bi(111) bilayer is studied using many-orbital tight-binding model, supported by the density-functional theory calculations, with a controllable spin-orbit coupling constant in tight-binding model. This effect is important in order to verify a topological nature of this material. We show that after closing of the energy gap leading to crossing of the valence and conduction bands, the second band inversion occurs within a valence band. We analyze orbital composition and spin textures of bands within different regimes. Around a Γ point, all spins align in one direction before the first band inversion. Moreover, a change of signs for some spin components after a band inversion is noticed. After the second band inversion, a significant change of orbital contribution of the top of the valence band is observed.

3

Electronic Shells of Dirac Fermions in Graphene Quantum Rings in a Magnetic Field

100%

Potasz P., Güçlü A., Hawrylak P.

Acta Physica Polonica A

|

2009

|

vol. 116

|

issue 5

832-834

EN

We present results of tight binding calculations demonstrating existence of degenerate electronic shells of Dirac fermions in narrow, charge neutral graphene quantum rings. We predict removal of degeneracy with finite magnetic field. We show, using a combination of tight binding and configuration interaction methods, that by filling a graphene ring with additional electrons this carbon based structure with half-filled shell acquires a finite magnetic moment.

4

Analysis of Optical Properties of MoS₂ Monolayer using Minimal-Basis Tight-Binding Models

88%

Nouri N., Potasz P., Zia Borujeni S., Wójs A., Rashedi G.

Acta Physica Polonica A

|

2017

|

vol. 132

|

issue 2

313-315

EN

Optical properties of transition metal dichalcogenides monolayer of MoS₂ are analyzed using multi-orbital tight-binding models with only Mo d-orbitals (three-band model) and with an inclusion of S p-orbitals (six-band model). We look at band structures, momentum matrix elements between valence and conduction band, and joint optical density of states. Good agreement between the two models is shown in a vicinity of K point of the Brillouin zone. On line connecting K and Γp points, a local conduction band minimum at Q point is recovered only by six-band model in agreement with density functional theory and experimental results. We show that optical transitions at this point are active for both light polarizations. A peak in joint optical density of states is also seen at this point suggesting its potentially important role in a proper description of excitonic effects.

Refine search results

4 Acta Physica Polonica A

1 2017

2 2016

1 2009

4 Potasz P.

2 Wójs A.

1 Bieniek M.

1 Güçlü A.

1 Hawrylak P.

1 Nouri N.

1 Piekarska A.

1 Rashedi G.

1 Woźniak T.

1 Zia Borujeni S.

Search results

Analysis of the Quantum Spin Hall and Quantum Anomalous Hall Effects in a Two-Dimensional Decorated Lattice Using Entanglement Spectrum

Study of Spin-Orbit Coupling Effect on Bismuth (111) Bilayer

Electronic Shells of Dirac Fermions in Graphene Quantum Rings in a Magnetic Field

Analysis of Optical Properties of MoS₂ Monolayer using Minimal-Basis Tight-Binding Models