Charge transport in dual gated bilayer graphene with Corbino geometry

TL;DR

This study investigates charge transport in dual-gated bilayer graphene with Corbino geometry, revealing the electric-field-dependent band gap and showing edge transport is negligible, using temperature-dependent resistance measurements and a two-channel conductance model.

Contribution

It provides the first detailed analysis of charge transport in dual-gated bilayer graphene in Corbino geometry, emphasizing the role of bulk conduction mechanisms.

Findings

Electric-field-dependent band gap matches infrared absorption data

Transport dominated by bulk channels, not edge effects

Temperature-dependent resistance explained by two-channel model

Abstract

The resistance of dual-gated bilayer graphene is measured as a function of temperature and gating electric fields in the Corbino geometry which precludes edge transport. The temperature-dependent resistance is quantitatively described by a two channel conductance model including parallel thermal activation and variable range hopping channels, which gives the electric-field-dependent band gap whose magnitude is found to be in good agreement with infrared absorption experiments. Low temperature transport is similar to previous studies of dual-gated bilayer graphene with edges, suggesting that edge transport does not play an important role.