Precision Quantum Hall Resistance Measurement on Epitaxial Graphene Device in Low Magnetic Field

TL;DR

This study demonstrates highly precise quantum Hall resistance measurements on epitaxial graphene at low magnetic fields, achieving deviations within parts per million, which advances quantum resistance standards.

Contribution

It presents the first precise quantum Hall resistance measurements on epitaxial graphene at magnetic fields as low as 3 T using a cryogenic current comparator.

Findings

Hall resistance deviation within 3.5 parts in 10^8 at 8 T

Deviation remained below 0.35 ppm down to 3 T

High biasing current enabled accurate measurements

Abstract

Precision quantum Hall resistance (QHR) measurements were performed on large-area epitaxial graphene device at low magnetic fields (B = 2 T - 8 T) at temperature T = 1.5 K. Hall resistance was measured using Cryogenic Current Comparator resistance bridge with high biasing current Isd = 40 micro ampere. The results showed that at B = 8 T the relative deviation of Hall resistance from the expected quantized value h/2e2 is within experimental uncertainty of 3.5 parts in 108 and remained below 0.35 parts per million (ppm) down to B = 3 T.