Graphene with time-dependent spin-orbit coupling: Truncated Magnus expansion approach

TL;DR

This paper investigates the effects of time-dependent Rashba spin-orbit coupling in graphene, employing the Magnus expansion to approximate the quasienergy spectrum and comparing it with exact numerical solutions.

Contribution

It introduces a semi-analytical approach using the Magnus expansion to analyze the quasienergy spectrum in driven graphene systems with spin-orbit coupling.

Findings

Magnus expansion provides a valid approximation within certain parameter boundaries.

Comparison with numerical solutions clarifies the limits of the semi-analytical method.

The approach captures key features of the quasienergy spectrum under ac-driven conditions.

Abstract

We analyze the role of ac-driven Rashba spin-orbit coupling in monolayer graphene including a spin-dependent mass term. Using the Magnus expansion as a semi-analytical approximation scheme a full account of the quasienergie spectrum of spin states is given. We discuss the subtleties arising in correctly applying the Magnus expansion technique in order to determine the quasienergy spectrum. Comparison to the exact numerical solution gives appropriate boundaries to the validity of the Magnus expansion solution.