Quasiparticle Transformation During a Metal-Insulator Transition in Graphene

TL;DR

This study demonstrates a metal-insulator transition in hydrogen-dosed graphene on SiC(0001), characterized by increased resistance and spectral anomalies, indicating a transition to a localized electronic state.

Contribution

It provides direct experimental evidence of a metal-insulator transition in graphene induced by atomic hydrogen, revealing quasiparticle breakdown and non-Fermi liquid behavior.

Findings

Resistance increases by about 4 orders of magnitude.

Spectral function shows non-Fermi Liquid behavior.

Evidence suggests transition to a localized ground state.

Abstract

Here we show, with simultaneous transport and photoemission measurements, that the graphene terminated SiC(0001) surface undergoes a metal-insulator transition (MIT) upon dosingwith small amounts of atomic hydrogen. We find the room temperature resistance increases by about 4 orders of magnitude, a transition accompanied by anomalies in the momentum-resolved spectral function including a non-Fermi Liquid behaviour and a breakdown of the quasiparticle picture. These effects are discussed in terms of a possible transition to a strongly (Anderson) localized ground state.