Young Woo Nam
August 18(Thu) - August 18(Thu), 2016
Interaction-induced insulating state in thick multilayer graphene
Dr. Young Woo Nam/ University of Geneva
Upon increasing their thickness, the electronic properties of graphene multilayers should approach those of graphite, a semi-metal that stays conducting at low temperature. Recent studies, however, found that ultra-clean suspended 4-layer graphene devices are insulating due to electron-electron interactions. Along with previous experiments, this result led to the suggestion of an even-odd effect, with all even multilayers becoming insulating and all odd ones staying conducting at low temperature. Here we demonstrate the validity of this hypothesis by showing that also 6- and 8-layer graphene become insulating just like 4-layer graphene. The behavior observed experimentally, a rare example of systematic electron-electron interactions effects, confirms to a phenomenological scenario of which we discuss the validity and possible breakdown mechanisms.