Large-scale five- and seven-junction epitaxial graphene devices

TL;DR

This paper demonstrates large-scale five- and seven-junction epitaxial graphene devices that enable measurement of fractional quantized Hall resistance values, validated through experiments, simulations, and analytical models, using simple fabrication techniques.

Contribution

It introduces large-scale multi-junction graphene devices and validates fractional quantum Hall resistance measurements with simulations and analytical models.

Findings

Measurement of fractional R_H at i=2 plateau

Validation of simulations and analytical models

Successful fabrication using ultraviolet lithography

Abstract

The utilization of multiple current terminals on millimeter-scale graphene p-n junction devices has enabled the measurement of many atypical, fractional multiples of the quantized Hall resistance at the i=2 plateau. These fractions take the form a/b R_H and can be determined both analytically and by simulations. These experiments validate the use of either the LTspice circuit simulator or the analytical framework recently presented in similar work. Furthermore, the production of several devices with large-scale junctions substantiates the approach of using simple ultraviolet lithography to obtain junctions of sufficient sharpness.