Charge density waves in disordered media circumventing the Imry-Ma argument

TL;DR

This paper demonstrates that in disordered one-dimensional systems, correlated disorder can stabilize charge density waves against the Imry-Ma argument, revealing new ways disorder influences ordered phases.

Contribution

The study shows how correlated disorder can circumvent the Imry-Ma argument, enabling stable ordered states with discrete symmetry breaking in disordered 1D systems.

Findings

Charge density waves remain stable up to a finite disorder strength.

Correlated disorder can bypass the Imry-Ma mechanism.

Disorder can destroy order through mechanisms other than Imry-Ma.

Abstract

Two powerful theoretical predictions, Anderson localization and the Imry-Ma argument, impose significant restrictions on the phases of matter that can exist in the presence of even the smallest amount of disorder in one-dimensional systems. These predictions forbid conducting states and ordered states respectively. It was thus remarkable that a mechanism to circumvent Anderson localization relying on the presence of correlated disorder was found, that is also realized in certain biomolecular systems. In a similar manner, we show that the Imry-Ma argument can be circumvented resulting in the formation of stable ordered states with discrete broken symmetries in disordered one dimensional systems. Specifically, we simulate a family of Hamiltonians of spinless fermions with correlated disorder and interactions, where we find that a charge density wave is stable up to a finite critical disorder strength. Having circumvented the Imry-Ma mechanism, we then investigate other mechanisms by which disorder can destroy an ordered state.