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arXiv · 1401.0299

Disorder and magnetic-field induced breakdown of helical edge conduction in an inverted electron-hole bilayer

D. I. Pikulin·T. Hyart·Shuo Mi·J. Tworzydło·M. Wimmer·C. W. J. Beenakker
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Abstract

We calculate the conductance of a two-dimensional bilayer with inverted electron-hole bands, to study the sensitivity of the quantum spin Hall insulator (with helical edge conduction) to the combination of electrostatic disorder and a perpendicular magnetic field. The characteristic breakdown field for helical edge conduction splits into two fields with increasing disorder, a field $B_{c}$ for the transition into a quantum Hall insulator (supporting chiral edge conduction) and a smaller field $B'_{c}$ for the transition to bulk conduction in a quasi-metallic regime. The spatial separation of the inverted bands, typical for broken-gap InAs/GaSb quantum wells, is essential for the magnetic-field induced bulk conduction --- there is no such regime in HgTe quantum wells.

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D. I. Pikulin, T. Hyart, Shuo Mi, J. Tworzydło, M. Wimmer, C. W. J. Beenakker. 2014-04-30. Disorder and magnetic-field induced breakdown of helical edge conduction in an inverted electron-hole bilayer. https://doi.org/10.1103/physrevb.89.161403

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