Quantisation of Hopping Magnetoresistance Prefactor in Strongly Correlated Two-Dimensional Electron Systems

TL;DR

This study reveals universal quantization of the hopping magnetoresistance prefactor in strongly correlated 2D electron systems, showing resistance quantization at fundamental quantum resistance values, indicating a novel electronic phase.

Contribution

It uncovers quantized values of the hopping magnetoresistance prefactor in strongly interacting 2DES, suggesting a new correlated electronic phase.

Findings

Prefactor decreases exponentially with electron density

Prefactor saturates to a finite universal value

Quantization at h/e^2 and 1/2 h/e^2 observed

Abstract

We report an universal behaviour of hopping transport in strongly interacting mesoscopic two-dimensional electron systems (2DES). In a certain window of background disorder, the resistivity at low perpendicular magnetic fields follows the expected relation $\rho(B_\perp) = \rho_{\rm{B}}\exp(\alpha B_\perp^2)$. The prefactor $\rho_{\rm{B}}$ decreases exponentially with increasing electron density but saturates to a finite value at higher densities. Strikingly, this value is found to be universal when expressed in terms of absolute resistance and and shows quantisation at $R_{\rm{B}}\approx h/e^2$ and $R_{\rm{B}}\approx 1/2$ $ h/e^2$. We suggest a strongly correlated electronic phase as a possible explanation.