Spin supercurrent in superconductor/ferromagnet van-der-Waals heterostructures

TL;DR

This paper explores how charge supercurrents induce dissipationless spin transport in van der Waals superconductor heterostructures, revealing controllable spin currents via spin-orbit coupling, magnetic fields, and gating.

Contribution

It demonstrates the emergence of nonunitary triplet correlations and controllable spin currents in superconductor/ferromagnet heterostructures without external magnetic fields.

Findings

Dissipationless spin currents arise from combined spin-orbit coupling and Zeeman effects.

Spin current exhibits rectification behavior.

Gating controls the amplitude and sign of the spin current.

Abstract

We study dissipationless spin transport induced by a charge supercurrent in a monolayer van der Waals superconductor under the applied magnetic field and in a bilayer superconductor/ferromagnet (S/F) heterostructure with no external field. It is shown that in both cases a combined action of the Ising-type spin-orbit coupling and the Zeeman field results in appearance of a nonunitary superconducting triplet correlations with nonzero average Cooper pair spin, which carry spin current in the presence of a condensate motion. Properties of this dissipationless spin current are investigated. In particular, it is shown that it manifests a rectification effect. In addition, in S/F heterostructures the amplitude and the sign of the spin current are controlled by gating.