Direct Measurement of the Fermi Energy in Graphene Using a Double Layer Structure

TL;DR

This paper introduces a novel double-layer technique for directly measuring the Fermi energy in graphene, enabling precise determination of electronic properties like Fermi velocity and Landau level characteristics.

Contribution

The paper presents a new method for directly measuring the Fermi energy in graphene using a double-layer structure, providing insights into Landau level broadening and electronic properties.

Findings

Fermi energy measured as a function of density in graphene.

Determined Fermi velocity and Landau level spacing.

Found increased broadening of the N=0 Landau level.

Abstract

We describe a technique which allows a direct measurement of the relative Fermi energy in an electron system using a double layer structure, where graphene is one of the two layers. We illustrate this method by probing the Fermi energy as a function of density in a graphene monolayer, at zero and in high magnetic fields. This technique allows us to determine the Fermi velocity, Landau level spacing, and Landau level broadening in graphene. We find that the N=0 Landau level broadening is larger by comparison to the broadening of upper and lower Landau levels.