Spin-valley Silin modes in graphene with substrate-induced spin-orbit coupling

TL;DR

This paper predicts and analyzes generalized Silin modes in monolayer graphene with substrate-induced spin-orbit coupling, revealing their excitation via AC electric fields and their impact on optical conductivity.

Contribution

It develops a gauge-invariant kinetic equation for multivalley Fermi liquids and demonstrates the existence of generalized Silin modes in graphene with SOC.

Findings

Generalized Silin modes can be excited in graphene with SOC.

These modes influence the optical conductivity.

The kinetic equation accounts for Berry curvature effects.

Abstract

In the presence of external magnetic field the Fermi-liquid state supports oscillatory spin modes known as Silin modes. We predict the existence of the generalized Silin modes in a multivalley system, monolayer graphene. A gauge- and Berry-gauge- invariant kinetic equation for a multivalley Fermi liquid is developed and applied to the case of graphene with extrinsic spin-orbit coupling (SOC). The interplay of SOC and Berry curvature allows for the excitation of generalized Silin modes in the spin and valley-staggered-spin channels via an AC electric field. The resonant contributions from these modes to the optical conductivity are calculated.