EFFECT OF INTERACTION IN ONE-DIMENSIONAL TOPOLOGICAL INSULATOR

2013 ◽  
Vol 27 (07) ◽  
pp. 1361001
Author(s):  
HUAIMING GUO ◽  
SHUN-QING SHEN
Keyword(s):  
Topological Insulator ◽  
Cold Atoms ◽  
Berry Phase ◽  
Repulsive Interaction ◽  
Edge States ◽  
One Dimensional ◽  
Diagonalization Method ◽  
Half Filling ◽  
The One ◽  
Exact Diagonalization Method

The one-dimensional interacting topological insulator is studied by means of exact diagonalization method. The topological properties are examined with the existence of the edge states and the quantized berry phase at half-filling. It is found that the topological phases are not only robust to small repulsive interactions but also are stabilized by small attractive interactions and also finite repulsive interaction can drive a topological nontrivial phase into a trivial one while the attractive interaction can drive a trivial phase into a nontrivial one. These results could be realized experimentally using cold atoms trapped in the 1D optical lattice.

scholarly journals Quasistationary states in a quantum dot formed at the edge of a topological insulator by magnetic barriers with finite transparency

2021 ◽  
Vol 2103 (1) ◽  
pp. 012201
Author(s):  
D V Khomitsky ◽  
E A Lavrukhina
Keyword(s):  
Topological Insulator ◽  
Two Dimensional ◽  
Edge States ◽  
Stationary Schrödinger Equation ◽  
Double Barrier ◽  
One Dimensional ◽  
Occupation Numbers ◽  
The One ◽  
Magnetic Barriers ◽  
Double Barrier Structure

Abstract A model of quasistationary states is constructed for the one-dimensional edge states propagating along the edge of a two-dimensional topological insulator based on HgTe/CdTe quantum well in the presence of magnetic barriers with finite transparency. The lifetimes of these quasistationary states are found analytically and numerically via different approaches including the solution of the stationary Schrödinger equation with complex energy and the solution of the transmission problem for a double barrier structure. The results can serve as a guide for determining the parameters of magnetic barriers creating the quantum dots where the lifetimes for the broadened discrete levels are long enough for manipulation with their occupation numbers by external fields.

Quantum entanglement in some topological insulator models

2019 ◽  
Vol 33 (24) ◽  
pp. 1950284 ◽  
Author(s):  
L. S. Lima
Keyword(s):  
Quantum Entanglement ◽  
Topological Insulator ◽  
Topological Charge ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Model Case ◽  
Topological Transition ◽  
One Dimensional ◽  
Zhang Model ◽  
The One

Quantum entanglement is studied in the neighborhood of a topological transition in some topological insulator models such as the two-dimensional Qi–Wu–Zhang model or Chern insulator. The system describes electrons hopping in two-dimensional chains. For the one-dimensional model case, there exist staggered hopping amplitudes. Our results show a strong effect of sudden variation of the topological charge Q in the neighborhood of phase transition on quantum entanglement for all the cases analyzed.

The Saxon–Hutner Theorem, its Converse Theorem and their Applications to Localization and Delocalization Problems in Binary Quasiperiodic Lattices

1997 ◽  
Vol 11 (18) ◽  
pp. 2157-2182 ◽  
Author(s):  
Kazumoto Iguchi
Keyword(s):  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Cantor Set ◽  
Localized States ◽  
Edge States ◽  
Converse Theorem ◽  
One Dimensional ◽  
The One ◽  
Fibonacci Lattice

In this paper we discuss the application of the Saxon–Hutner theorem and its converse theorem in one-dimensional binary disordered lattices to the one-dimensional binary quasiperiodic lattices. We first summarize some basic theorems in one-dimensional periodic lattices. We discuss how the bulk and edge states are treated in the transfer matrix method. Second, we review the Saxon–Hutner theorem and prove the converse theorem, using the so-called Fricke identities. Third, we present an alternative approach for a rigorous proof of the existence of a Cantor-set spectrum in the Fibonacci lattice and in the related binary quasiperiodic lattices by means of the theorems together with their trace map with the invariant I. We obtain that if I > 0, then the spectrum is always a Cantor set, which was first proved for the Fibonacci lattice by Sütö and generalized for other quasiperiodic lattices by Bellissard, Iochum, Scopolla, and Testard. Fourth, we rigorously prove the existence of extended states in the spectrum of a class of binary quasiperiodic lattices first studied by Kolář and Ali. Fifth, we discuss the so-called gap labeling theorem emphasized by Bellissard and the classic argument of Kohn and Thouless for localized states in a one-dimensional disordered lattice in terms of the language of the transfer matrix method.

scholarly journals MOMENTUM DISTRIBUTION OF ITINERANT ELECTRONS IN THE ONE-DIMENSIONAL FALICOV–KIMBALL MODEL

2003 ◽  
Vol 17 (27) ◽  
pp. 4897-4911 ◽  
Author(s):  
PAVOL FARKAŠOVSKÝ
Keyword(s):  
Momentum Distribution ◽  
Ground States ◽  
Local Maximum ◽  
Singular Behavior ◽  
Coulomb Interactions ◽  
Unusual Behavior ◽  
One Dimensional ◽  
Itinerant Electrons ◽  
Half Filling ◽  
The One

The momentum distribution nk of itinerant electrons in the one-dimensional Falicov–Kimball model is calculated for various ground-state phases. In particular, we examine the periodic phases with period two, three and four (that are ground-states for all Coulomb interactions) as well as the phase separated states (that are ground states for small Coulomb interactions). For all periodic phases examined the momentum distribution is a smooth function of k with no sign of any discontinuity or singular behavior at the Fermi surface k=kF. An unusual behavior of nk (a local maximum) is found at k=3kF for electron concentrations outside half-filling. For the phase separated ground states the momentum distribution nk exhibits discontinuity at k=k0<kF. This behavior is interpreted in terms of a Fermi liquid.

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