Spin-Nernst Effect in Time-Reversal-Invariant Topological Superconductors

TL;DR

This paper demonstrates that the spin-Nernst effect can serve as a definitive experimental signature for identifying helical Cooper pairs in time-reversal invariant topological superconductors, based on impurity scattering effects.

Contribution

It reveals that the spin-Nernst effect uniquely indicates topological superconducting order and depends on impurity scattering phase shifts, providing a new diagnostic tool.

Findings

Spin-Nernst effect arises from asymmetric quasiparticle scattering.

The effect's sign and magnitude depend on impurity phase shifts.

It offers a smoking-gun evidence for helical Cooper pairs.

Abstract

We investigate the spin-Nernst effect in time-reversal invariant topological superconductors, and show that it provides a smoking-gun evidence for helical Cooper pairs. The spin-Nernst effect stems from asymmetric, in spin space, scattering of quasiparticles at nonmagnetic impurities, and generates a transverse spin current by the temperature gradient. Both the sign and the magnitude of the effect sensitively depend on the scattering phase shift at impurity sites. Therefore the spin-Nernst effect is uniquely suitable for identifying time-reversal invariant topological superconducting orders.