Spin and electric currents induced by a spin-motive force in two-dimensional Dirac semimetals protected by nonsymmorphic symmetries

TL;DR

This paper theoretically investigates how spin-motive forces generate spin and charge currents in a 2D Dirac semimetal with nonsymmorphic symmetries, revealing non-zero spin conductivity and dissipationless spin currents at charge neutrality.

Contribution

It demonstrates the effects of nonsymmorphic symmetry constraints on spin and charge current responses in 2D Dirac semimetals, including dissipationless spin currents at neutrality.

Findings

Pure spin current remains non-zero at the Dirac node.

Out-of-plane spin induces pure spin current, in-plane spin induces charge current.

Dissipationless spin current appears at charge neutrality.

Abstract

We theoretically study the spin and charge currents induced by a spin-motive force in a two-dimensional Dirac semimetal protected by nonsymmorphic symmetries. Glide mirror plane symmetry, a nonsymmorphic symmetry, leads to a constraint to the induced current; the spin-motive force acting on out-of-plane spin (in-plane spin) induces the pure spin (charge) current. We calculate the response function to the spin-motive force in linear response theory and find that the conductivity for the pure spin current remains non-zero even if the Fermi energy is crossing the node of linear dispersion. We also find that the dissipationless spin current is induced at the charge neutral point.