Tunnelling conductance of strongly correlated materials: ABC-stacked trilayer graphene

Jongbae Hong, D. S. L. Abergel

Published 2014-11-20Version 1

Multilayer graphene is currently attracting much attention as a possible platform for transistors, spintronic devices, and for its fundamental physics. Recently, tunnelling conductance measurements have been carried out as part of the ongoing effort to characterise the material. It is claimed that these measurements show that, in the absence of external electric and magnetic fields, and at low doping, ABC-stacked trilayer graphene may spontaneously develop a Mott-like insulating ground state. Here we show that in this strongly correlated regime, two-terminal conductance must be understood by a novel Kondo-like mechanism where electrons tunnel into the trilayer graphene via an entangled singlet state. By directly comparing our theory to experimental data, we simultaneously provide strong evidence for the tunnelling mechanism we promote, and explain features in the measured conductance of trilayer graphene.