Electron-spin to Phonon Coupling in Graphene Decorated with Heavy Adatoms

TL;DR

This paper investigates how heavy adatoms on graphene enhance spin-orbit coupling and induce a coupling between phonons and electron spins, affecting spin dynamics and potentially impacting spin transport and superconductivity.

Contribution

It systematically analyzes phonon-electron spin coupling in decorated graphene using group theory and tight-binding models, providing a foundation for future spin transport studies.

Findings

Spin-flip rate depends strongly on quasi-particle energy.

Spin-phonon coupling is significantly affected by adatom decoration.

Results suggest potential for tuning spin dynamics in graphene.

Abstract

The naturally weak spin-orbit coupling in Graphene can be largely enhanced by adatom deposition (e.g. Weeks et al. Phys. Rev. X 1, 021001 (2011)). However, the dynamics of the adatoms also induces a coupling between phonons and the electron spin. Using group theory and a tight-binding model, we systematically investigate the coupling between the low-energy in-plane phonons and the electron spin in single-layer graphene uniformly decorated with heavy adatoms. Our results provide the foundation for future investigations of spin transport and superconductivity in this system. In order to quantify the effect of the coupling to the lattice on the electronic spin dynamics, we compute the spin-flip rate of electrons and holes. We show that the latter exhibits a strong dependence on the quasi-particle energy and system temperature.