Zero external magnetic field quantum standard of resistance at the 10-9 level

TL;DR

This paper demonstrates a highly precise quantum resistance standard at zero magnetic field using magnetic topological insulators, achieving a relative uncertainty of 10^-9, advancing quantum metrology.

Contribution

It reports the first highly accurate zero-field quantum resistance standard based on the quantum anomalous Hall effect in magnetic topological insulators.

Findings

Achieved resistance quantization with 10^-9 relative uncertainty.

Set a new benchmark for quantization accuracy in topological matter.

Validated the potential for zero-field quantum resistance standards.

Abstract

The quantum anomalous Hall effect holds promise as a disruptive innovation in condensed matter physics and metrology, as it gives access to Hall resistance quantization in terms of the von-Klitzing constant RK = h/e2 at zero external magnetic field. In this work, we study the accuracy of Hall resistance quantization in a device based on the magnetic topological insulator material (V,Bi,Sb)2Te3. We show that the relative deviation of the Hall resistance from RK at zero external magnetic field is (4.4 +/- 8.7) nohm/ohm when extrapolated to zero measurement current, and (8.6 +/- 6.7) nohm/ohm when extrapolated to zero longitudinal resistivity (each with combined standard uncertainty, k = 1), which sets a new benchmark for the quantization accuracy in topological matter. This precision and accuracy at the nohm/ohm level (or 10-9 of relative uncertainty) achieve the thresholds for relevant metrological applications and establish a zero external magnetic field quantum standard of resistance - an important step towards the integration of quantum-based voltage and resistance standards into a single universal quantum electrical reference.