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
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 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
Type: Article
Journal: Physical Review B
Volume: 100
ISSN: 2469-9950
Publication date: 25.10.2019
Publication status: Published
Peer reviewed: Yes
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)

BibTeX

@article{74c1d6eda975428aa9fadf17ece6a739,
title = "Voltage-tunable Majorana bound states in time-reversal symmetric bilayer quantum spin Hall hybrid systems",
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 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.",
author = "F. Schulz and Budich, {J. C.} and Novik, {E. G.} and P. Recher and B. Trauzettel",
note = "Funding information: We thank C. Fleckenstein, F. Keidel, J. Klinovaja, D. Loss, H. W. Schumacher, and P. Silvestrov for fruitful discussions. We acknowledge financial support by the DFG (SPP1666, SFB1170 “ToCoTronics,” SFB1143 “Correlated Magnetism: From Frustration to Topology” ID 247310070, AS 327/5-1, RE 2978/7-1, and the DACH project on “Majorana and parafermions in topological insulators”), the ENB Gradu ate school on “Topological Insulators,” and the W{\"u}rzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter (EXC 2147, project-id 39085490) and the DFG-EXC 2123, Quantum Frontiers.",
year = "2019",
month = oct,
day = "25",
doi = "10.1103/physrevb.100.165420",
language = "English",
volume = "100",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Institute of Physics",
number = "16",
}