Robustness of Quantum Spin Hall Effect in an External Magnetic Field

Abstract

The edge states in the quantum spin Hall effect are expected to be protected by time reversal symmetry. The experimental observation of the quantized conductance was reported in the InAs/GaSb quantum well {[}Du et al, arXiv:1306.1925{]}, up to a large magnetic field, which raises a question on the robustness of the edge states in the quantum spin Hall effect under time reversal symmetry breaking. Here we present a theoretical calculation on topological invariants for the Benevig-Hughes-Zhang model in an external magnetic field, and find that the quantum spin Hall effect retains robust up to a large magnetic field. The critical value of the magnetic field breaking the quantum spin Hall effect is dominantly determined by the band gap at the $\Gamma$ point instead of the indirect band gap between the conduction and valence bands. This illustrates that the quantum spin Hall effect could persist even under time reversal symmetry breaking.

9 pages, 5 figures, to appear in Phys. Rev. B

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Cited by in corpus (9)

• Quantum Transport in Topological Semimetals under Magnetic Fields
• Observation of the dual quantum spin Hall insulator by density-tuned correlations in a van der Waals monolayer
• Hidden edge Dirac point and robust quantum edge transport in InAs/GaSb quantum wells
• Quantum Hall effect originated from helical edge states in Cd${}_3$As${}_2$
• Majorana bound states in topological insulators with hidden Dirac points
• Spin and charge transport through helical Aharonov-Bohm interferometer with strong magnetic impurity
• Chern insulating state in laterally patterned semiconductor heterostructures
• High-field magnetoconductivity of topological semimetals with short-range potential
• Anomalous flux periodicity in proximitised quantum spin Hall constrictions