Mimicing the Kane-Mele type spin orbit interaction by spin-flexual phonon coupling in graphene devices

TL;DR

This paper demonstrates that decorating graphene with EDTA-Dy molecules can mimic Kane-Mele type spin orbit interaction through spin-flexural phonon coupling, enhancing quantum Hall effects and carrier mobility.

Contribution

It introduces a novel method of inducing Kane-Mele type SOI in graphene via spin-flexural phonon coupling without extrinsic Rashba effects.

Findings

Suppressed weak localization at equal carrier densities

Elliot-Yafet spin relaxation with interaction strength of 3.3 meV

Improved quantum Hall plateaus after decoration

Abstract

On the efforts of enhancing the spin orbit interaction (SOI) of graphene for seeking the dissipationless quantum spin Hall devices, unique Kane-Mele type SOI and high mobility samples are desired. However, common external decoration often introduces extrinsic Rashba-type SOI and simultaneous impurity scattering. Here we show, by the EDTA-Dy molecule decorating, the Kane-Mele type SOI is mimicked with even improved carrier mobility. It is evidenced by the suppressed weak localization at equal carrier densities and simultaneous Elliot-Yafet spin relaxation. The extracted spin scattering time is monotonically dependent on the carrier elastic scattering time, where the Elliot-Yafet plot gives the interaction strength of 3.3 meV. Improved quantum Hall plateaus can be even seen after the external operation. This is attributed to the spin-flexural phonon coupling induced by the enhanced graphene ripples, as revealed by the in-plane magnetotransport measurement.