Non-Ergodicity & Microscopic Symmetry Breaking of the Conductance Fluctuations in Disordered Mesoscopic Graphene

TL;DR

This paper reveals non-ergodic conductance fluctuations in disordered graphene, showing anisotropic responses to magnetic fields and challenging existing quantum interference models for mesoscopic systems.

Contribution

It demonstrates the breakdown of ergodicity in graphene conductance fluctuations and highlights the complex, anisotropic quantum interference effects unique to graphene.

Findings

Conductance fluctuations are smaller when varying Fermi energy compared to magnetic field.

Fluctuations show anisotropic response to magnetic field orientation.

Graphene exhibits complex quantum interference behavior beyond conventional systems.

Abstract

We show a dramatic deviation from ergodicity for the conductance fluctuations in graphene. In marked contrast to the ergodicity of dirty metals, fluctuations generated by varying magnetic field are shown to be much smaller than those obtained when sweeping Fermi energy. They also exhibit a strongly anisotropic response to the symmetry-breaking effects of a magnetic field, when applied perpendicular or parallel to the graphene plane. These results reveal a complex picture of quantum interference in graphene, whose description appears more challenging than for conventional mesoscopic systems.