scholarly journals Local versus nonlocal correlation effects in interacting quantum spin Hall insulators

2021 ◽  
Vol 104 (23) ◽  
Author(s):  
L. Crippa ◽  
A. Amaricci ◽  
S. Adler ◽  
G. Sangiovanni ◽  
M. Capone
Keyword(s):  
Quantum Spin ◽  
Correlation Effects ◽  
Nonlocal Correlation ◽  
Quantum Spin Hall

scholarly journals THE CHARACTERIZATION OF TOPOLOGICAL PROPERTIES IN QUANTUM MONTE CARLO SIMULATIONS OF THE KANE–MELE–HUBBARD MODEL

2013 ◽  
Vol 28 (01) ◽  
pp. 1430001 ◽  
Author(s):  
ZI YANG MENG ◽  
HSIANG-HSUAN HUNG ◽  
THOMAS C. LANG
Keyword(s):  
Monte Carlo ◽  
Hubbard Model ◽  
Green’S Function ◽  
Green's Function ◽  
Quantum Monte Carlo ◽  
Quantum Spin ◽  
Topological Phase ◽  
Correlation Effects ◽  
Topological Properties ◽  
Quantum Spin Hall

Topological insulators present a bulk gap, but allow for dissipationless spin transport along the edges. These exotic states are characterized by the Z2 topological invariant and are protected by time-reversal symmetry. The Kane–Mele model is one model to realize this topological class in two dimensions, also called the quantum spin Hall state. In this brief review article, we provide a pedagogical introduction to the influence of correlation effects in the quantum spin Hall states, with special focus on the half-filled Kane–Mele–Hubbard model, solved by means of unbiased determinant quantum Monte Carlo (QMC) simulations. We explain the idea of identifying the topological insulator via π-flux insertion, the Z2 invariant and the associated behavior of the zero-frequency Green's function, as well as the spin Chern number in parameter-driven topological phase transitions. The examples considered are two descendants of the Kane–Mele–Hubbard model, the generalized and dimerized Kane–Mele–Hubbard model. From the Z2 index, spin Chern numbers and the Green's function behavior, one can observe that correlation effects induce shifts of the topological phase boundaries. Although the implementation of these topological quantities has been successfully employed in QMC simulations to describe the topological phase transition, we also point out their limitations as well as suggest possible future directions in using numerical methods to characterize topological properties of strongly correlated condensed matter systems.

A New Type of Large‐Gap Quantum Spin Hall Insulator Material ZrSe 5

2021 ◽  
Author(s):  
Xing Wang ◽  
Wenhui Wan ◽  
Yanfeng Ge ◽  
Jun Li ◽  
Yong Liu
Keyword(s):  
Quantum Spin ◽  
New Type ◽  
Quantum Spin Hall

scholarly journals Doping-Induced Quantum Spin Hall Insulator to Superconductor Transition

2021 ◽  
Vol 126 (20) ◽  
Author(s):  
Zhenjiu Wang ◽  
Yuhai Liu ◽  
Toshihiro Sato ◽  
Martin Hohenadler ◽  
Chong Wang ◽  
...  
Keyword(s):  
Quantum Spin ◽  
Quantum Spin Hall

scholarly journals Signature of Large-Gap Quantum Spin Hall State in the Layered Mineral Jacutingaite

Nano Letters ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 5207-5213 ◽  
Author(s):  
Konrád Kandrai ◽  
Péter Vancsó ◽  
Gergő Kukucska ◽  
János Koltai ◽  
György Baranka ◽  
...  
Keyword(s):  
Quantum Spin ◽  
Quantum Spin Hall

scholarly journals Emergent quantum Hall effects below 50 mT in a two-dimensional topological insulator

2020 ◽  
Vol 6 (26) ◽  
pp. eaba4625
Author(s):  
Saquib Shamim ◽  
Wouter Beugeling ◽  
Jan Böttcher ◽  
Pragya Shekhar ◽  
Andreas Budewitz ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Quantum Hall ◽  
Quantum Spin ◽  
Majorana Fermions ◽  
Quantum Spin Hall Effect ◽  
Topological Materials ◽  
Quantum Hall Effects ◽  
Hall Effects ◽  
Low Magnetic Field ◽  
Quantum Spin Hall

The realization of the quantum spin Hall effect in HgTe quantum wells has led to the development of topological materials, which, in combination with magnetism and superconductivity, are predicted to host chiral Majorana fermions. However, the large magnetization in conventional quantum anomalous Hall systems makes it challenging to induce superconductivity. Here, we report two different emergent quantum Hall effects in (Hg,Mn)Te quantum wells. First, a previously unidentified quantum Hall state emerges from the quantum spin Hall state at an exceptionally low magnetic field of ~50 mT. Second, tuning toward the bulk p-regime, we resolve quantum Hall plateaus at fields as low as 20 to 30 mT, where transport is dominated by a van Hove singularity in the valence band. These emergent quantum Hall phenomena rely critically on the topological band structure of HgTe, and their occurrence at very low fields makes them an ideal candidate for realizing chiral Majorana fermions.

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