Regensburg 2022 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 19: Topological Superconductors
TT 19.1: Talk
Wednesday, September 7, 2022, 11:45–12:00, H23
Periodic supercurrent oscillations in topological insulator nanowire Josephson junctions in an axial magnetic field — •Michael Barth1, Jacob Fuchs1, Cosimo Gorini1,2, and Klaus Richter1 — 1Institute of Theoretical Physics, University of Regensburg, D-93040 Regensburg, Germany — 2Université Paris-Saclay, CEA, CNRS, SPEC, 91191, Gif-sur-Yvette, France
Helical surface states of 3-dimensional topological insulator (TI) nanowires are expected to have very promising physical properties like forbidden backscattering [1]. Moreover it is predicted that a topological superconducting state which could possibly host Majorana fermions can be realized by bringing a normal s-wave superconductor in close proximity to a TI [2]. We theoretically study the influence of an axial magnetic field on the supercurrent flow in TI nanowire Josephson junctions. The wire is modeled by an effective 2 dimensional setup and we take into account the special surface geometry by incorporating the partial superconducting coverage of the wire circumference. By employing numerical tight-binding simulations [3] and a semiclassical analytical approach [4], we show that the critical current can exhibit periodic oscillations, where the period corresponds to half of the superconducting flux quantum.
[1] X.-L. Qi and S.-C. Zhang, Rev. Mod. Phys. 83, 1057 (2011)
[2] A. Cook and M. Franz, Phys. Rev. B 84, 201105(R) (2011)
[3] Kun Zuoet et al., Phys. Rev. Lett. 119, 187704 (2017)
[4] V. P. Ostroukh et al., Phys. Rev. B 94, 094514 (2016)