Graphene, universality of the quantum Hall effect and redefinition of the SI system

TL;DR

This paper demonstrates the universality of the quantum Hall effect across different materials, supporting the redefinition of SI units based on fundamental constants with unprecedented precision.

Contribution

It provides the most stringent test to date confirming the material independence of the quantum Hall effect, essential for SI redefinition.

Findings

No measurable difference in quantized resistance between graphene and GaAs/AlGaAs.

Measurement uncertainty of 8.6×10⁻¹¹ confirms universality.

Supports SI system redefinition based on fundamental constants.

Abstract

The Syst\`eme Internationale d'unit\'es (SI system) is about to undergo its biggest change in half a century by redefining the units for mass and current in terms of the fundamental constants h and e, respectively. This change crucially relies on the exactness of the relationships which link these constants to measurable quantities. Here we directly compare the integer quantum Hall effect in epitaxial graphene with that in GaAs/AlGaAs heterostructures. We find no difference of the quantized resistance value within the relative standard uncertainty of our measurement of 8.6\times10-11, being the most stringent test of the universality of the quantum Hall effect in terms of material independence.