Universal Scaling Theory of the Boundary Geometric Tensor in Disordered Metals

TL;DR

This paper studies the universal finite-size scaling behavior of the boundary quantum geometric tensor near the Anderson transition in disordered metals, revealing critical exponents and universal conductance fluctuations influenced by magnetic fields.

Contribution

It introduces a universal scaling framework for the boundary quantum geometric tensor near the Anderson transition, including effects of magnetic fields and isotropic conductance fluctuations.

Findings

QGT exhibits universal scaling near the transition

Crossover between orthogonal and unitary critical states identified

Universal and isotropic Hall conductance fluctuations predicted

Abstract

We investigate the finite-size scaling of the boundary quantum geometric tensor (QGT) numerically close to the Anderson localization transition in the presence of small external magnetic fields. The QGT exhibits universal scaling and reveals the crossover between the orthogonal and unitary critical states in weak random magnetic fields. The flow of the QGT near the critical points determines the critical exponents. Critical distributions of the QGT are universal and exhibit a remarkable isotropy even in a homogeneous magnetic field. We predict universal and isotropic Hall conductance fluctuations at the metal-insulator transition in an external magnetic field.