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arXiv · 1904.07166

Voltage-tunable Majorana bound states in time-reversal symmetric bilayer quantum spin Hall hybrid systems

F. Schulz·J. C. Budich·E. G. Novik·P. Recher·B. Trauzettel
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Abstract

We investigate hybrid structures based on a bilayer quantum spin Hall system in proximity to an s-wave superconductor as a platform to mimic time-reversal symmetric topological superconductors. In this bilayer setup, the induced pairing can be of intra- or inter-layer type, and domain walls of those different types of pairing potentials host Kramers partners (time-reversal conjugate pairs) of Majorana bound states. Interestingly, we discover that such topological interfaces providing Majorana bound states can also be achieved in an otherwise homogeneous system by a spatially dependent inter-layer gate voltage. This gate voltage causes the relative electron densities of the two layers to vary accordingly which suppresses the inter-layer pairing in regions with strong gate voltage. We identify particular transport signatures (zero-bias anomalies) in a five-terminal setup that are uniquely related to the presence of Kramers pairs of Majorana bound states.

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F. Schulz, J. C. Budich, E. G. Novik, P. Recher, B. Trauzettel. 2019-04-15. Voltage-tunable Majorana bound states in time-reversal symmetric bilayer quantum spin Hall hybrid systems. https://doi.org/10.1103/physrevb.100.165420

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