Electronic glasses from a broken gauge symmetry in disorder-free systems

TL;DR

This paper proposes a novel electronic mechanism for glass formation in disorder-free systems, where breaking of quantum gauge symmetry leads to a disordered, glassy phase without the need for quenched disorder.

Contribution

It introduces a new theoretical framework showing how glassy phases can emerge from gauge symmetry breaking in clean electronic systems, expanding understanding beyond traditional disorder-driven glasses.

Findings

Gauge symmetry breaking induces glassy phases in electronic systems.

Degeneracy lifting leads to disordered pairings resembling glass behavior.

The model connects gauge symmetry breaking with glass formation in superconductors.

Abstract

Glass phases can be stabilized by quenched disorders, as in most spin-glass materials, or self-generated through kinetic freezing in disorder-free systems. A canonical example of the latter is structural glasses, which have been extensively studied for many decades. Yet, how the rugged energy landscape of a glass phase is spontaneously generated in disorder-free systems remains one of the key questions in glass physics. Here we present a general electronic mechanism for the emergence of glassy phase using the example of itinerant electrons coupled to XY spins on a lattice. This model can also be be viewed as the mean-field theory of a superconducting system with attractive density-density interactions. Intriguingly, the electron gauge symmetry in the strong pairing limit gives rise to a macroscopic degeneracy of XY spins. In the presence of electron hopping that breaks the gauge symmetry, the lifting of the extensive degeneracy leads to a glass phase with disordered pairings. Our findings highlight a novel scenario in which a glassy state originates from the breaking of quantum gauge symmetry without quenched disorders.