Kondo effect in graphene with Rashba spin-orbit coupling

TL;DR

This paper investigates how Rashba spin-orbit coupling influences the Kondo effect in graphene, revealing tunable Kondo temperatures and quantum phase transitions through numerical analysis of an Anderson impurity model.

Contribution

It introduces a detailed analysis of the Kondo effect in graphene with Rashba coupling using the numerical renormalization group, highlighting the impact of spin-orbit interaction on many-body screening.

Findings

Rashba coupling significantly alters the Kondo temperature.

Quantum phase transition occurs at half filling between Kondo and free-moment phases.

Chemical potential tuning affects thermodynamic and spectral properties.

Abstract

We study the Kondo screening of a magnetic impurity adsorbed in graphene in the presence of Rashba spin-orbit interaction. The system is described by an effective single-channel Anderson impurity model, which we analyze using the numerical renormalization group. The nontrivial energy dependence of the host density of states gives rise to interesting behaviors under variation of the chemical potential or the spin-orbit coupling. Varying the Rashba coupling produces strong changes in the Kondo temperature characterizing the many-body screening of the impurity spin, and at half filling allows approach to a quantum phase transition separating the strong-coupling Kondo phase from a free-moment phase. Tuning the chemical potential close to sharp features of the hybridization function results in striking features in the temperature dependences of thermodynamic quantities and in the frequency dependence of the impurity spectral function.