Josephson phase shift and diode effect due to the inverse spin Hall effect
arXiv:2604.14521
The paper theoretically investigates how a supercurrent in a superconductor‑normal‑metal‑superconductor junction can generate a spin Hall effect and how an inhomogeneous magnetic field can produce an anomalous Josephson phase shift that leads to a diode effect, without requiring intrinsic structural inversion asymmetry.
Abstract
We theoretically study the direct and inverse spin Hall effects in a superconductor-normal metal-uperconductor junction induced by a spin-orbit interaction that is invariant under spatial inversion. We show that a supercurrent induces a spin Hall effect, leading to a static spin accumulation with opposite polarizations at the two edges, analogous to that in normal conductors. For the inverse effect, we consider a spatially inhomogeneous static magnetic field and show that it induces an anomalous phase shift, which, in the presence of higher harmonics, results in a diode effect. Unlike Rashba systems studied previously, the present mechanism does not require broken structural inversion symmetry, since an inhomogeneous magnetic field, equivalent to a spin current, breaks the inversion symmetry extrinsically.