Regensburg 2019 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 5: Topological insulators
HL 5.15: Talk
Monday, April 1, 2019, 13:15–13:30, H36
Majorana bound states in Phase-Controlled Josephson Junctions with Strong Spin-Orbit Coupling — •Benedikt Scharf1, Falko Pientka2, Hechen Ren3, Amir Yacoby4, Bertrand I. Halperin4, and Ewelina M. Hankiewicz1 — 1Institute for Theoretical Physics and Astrophysics, University of Würzburg, Würzburg, Germany — 2Max Planck Institute for the Physics of Complex Systems, Dresden, Germany — 3California Institute of Technology, Pasadena, California 91125, USA — 4Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
Topological superconductors based on Josephson junctions in two-dimensional electron gases (2DEGs) with strong Rashba spin-orbit coupling (SOC) offer an attractive alternative to wire-based setups [1,2]. Here, we elucidate how phase-controlled Josephson junctions with an arbitrary combination of Rashba and Dresselhaus SOC can also host Majorana bound states (MBS) for a wide range of parameters as long as the magnetic field is oriented appropriately. Hence, MBS based on Josephson junctions can appear in a wide class of 2DEGs. We study the effect of SOC, the Zeeman energies, the superconducting phase difference and normal reflection to create a full topological phase diagram and find the optimal stability region to observe MBS. Finally, we study the role of the Doppler effect that can arise due to the magnetic-field-induced local gradient of the superconducting phase in these junctions. [1] F. Pientka, et al. Phys Rev X 7, 021032 (2017). [2] H. Ren, et al. arXiv:1809.03076.