Superconducting Diode Effect in Selectively-Grown Topological Insulator based Josephson Junctions

arXiv (Cornell University)

Abstract

The Josephson diode effect, where the critical current magnitude depends on its direction, arises when both time-reversal and inversion symmetries are broken - often achieved by a combination of spin-orbit interaction and applied magnetic fields. Taking advantage of the strong spin-orbit coupling inherent in three-dimensional topological insulators, we study this phenomenon in Nb/Bi$_{0.8}$Sb$_{1.2}$Te$_3$/Nb Josephson weak-link junctions. Under an in-plane magnetic field perpendicular to the current direction, we observe a pronounced Josephson diode effect with efficiencies up to 7%. A crucial component of this behavior is the non-sinusoidal current-phase relationship and an anomalous phase shift, which we attribute to the presence of a ballistic supercurrent component due to the surface states. These findings open up new avenues for harnessing and controlling the Josephson diode effect in topological material systems.

Authors 4

1. Gerrit Behner Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology , Jülich-Aachen Research Alliance , Forschungszentrum Jülich and RWTH Aachen University , Germany

   Peter Grünberg Institut (PGI-9) , Forschungszentrum Jülich , 52425 Jülich , Germany

2. Abdur Rehman Jalil Aachen JARA-Fundamentals of Future Information Technology

   Forschungszentrum Jülich · Jülich Aachen Research Alliance · RWTH Aachen University

   Affiliation as printed

   JARA-Fundamentals of Future Information Technology , Jülich-Aachen Research Alliance , Forschungszentrum Jülich and RWTH Aachen University , Germany

   Peter Grünberg Institut (PGI-9) , Forschungszentrum Jülich , 52425 Jülich , Germany

3. Detlev Grützmacher
4. Thomas Schäpers