Edelstein Effect Induced Superconducting Diode Effect in Inversion Symmetry Breaking MoTe₂ Josephson Junctions

Abstract

Superconducting diode effect (SDE) with nonreciprocal supercurrent transport has attracted intense attention recently, not only for its intriguing physics, but also for its great application potential in superconducting circuits. It is revealed in this work that planar Josephson junctions (JJs) based on type‐II Weyl semimetal (WSM) MoTe2 can exhibit a prominent SDE due to the emergence of asymmetric Josephson effect (AJE) in perpendicular magnetic fields. The AJE manifests itself in a very large asymmetry in the critical supercurrents with respect to the current direction. The sign of this asymmetry can also be effectively modulated by the external magnetic field. Considering the special noncentrosymmetric crystal symmetry of MoTe2, this AJE is understood in terms of the Edelstein effect, which induces a nontrivial phase shift in the current phase relation of the junctions. Besides these, it is further demonstrated that the rectification of supercurrent in such MoTe2 JJs with the rectification efficiency up to 50.4%, unveiling the great application potential of WSMs in superconducting electronics.

Theory of spin and orbital Edelstein effects

“…The theory of the magnetoelectric effect in polar superconductors has been extended to other noncentrosymmetric superconductors [230,[232][233][234][235][236][237]. Experimental signatures of the Edelstein effect have been found in MoTe 2 -based planar Josephson junctions via the observation of a superconducting diode effect [238].…”

Nonreciprocal superconducting transport and the spin Hall effect in gyrotropic structures

“…All gyrotropic materials support non-reciprocal transport if time-reversal symmetry is broken, for example by a magnetic field. Examples of gyrotropic materials that are currently used in proposals and realizations for superconducting diodes are, apart from the Rashba superconductors, MoTe 2 and WeTe 2 [71,72].…”