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

authored by
F. Schulz, J. C. Budich, E. G. Novik, P. Recher, B. Trauzettel

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 interlayer 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 interlayer gate voltage. This gate voltage causes the relative electron densities of the two layers to vary accordingly, which suppresses the interlayer pairing in regions with strong gate voltage. We identify particular transport signatures (zero-bias anomalies) in a five-terminal setup that are clearly related to the presence of Kramers pairs of Majorana bound states.

External Organisation(s)
University of Basel
Technische Universität Dresden
Technische Universität Braunschweig
Julius Maximilian University of Würzburg
Cluster of Excellence ct.qmat - Complexity and Topology in Quantum Matter
Physical Review B
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Electronic, Optical and Magnetic Materials, Condensed Matter Physics
Electronic version(s)
https://doi.org/10.1103/physrevb.100.165420 (Access: Closed)