Long-range order and pinning of charge-density waves in competition with superconductivity

TL;DR

This paper investigates how charge-density-wave order interacts with superconductivity in layered cuprates, showing that weak magnetic fields can induce long-range order in clean systems, but disorder limits this to finite correlations.

Contribution

It introduces a model demonstrating that magnetic fields can stabilize long-range charge-density-wave order, and explains how disorder affects this order in cuprate superconductors.

Findings

Weak magnetic fields stabilize long-range charge order in clean systems.

Disorder disrupts interhalo coherence, limiting correlation length.

Interlayer coupling enhances correlations above a certain field.

Abstract

Recent experiments show that charge-density-wave correlations are prevalent in underdoped cuprate superconductors. The correlations are short ranged at weak magnetic fields but their intensity and spatial extent increase rapidly at low temperatures beyond a crossover field. Here we consider the possibility of long-range charge-density-wave order in a model of a layered system where such order competes with superconductivity.We show that in the clean limit, low-temperature long-range order is stabilized by arbitrarily weak magnetic fields. This apparent discrepancy with the experiments is resolved by the presence of disorder. Like the field, disorder nucleates halos of charge-density wave, but unlike the former it also disrupts interhalo coherence, leading to a correlation length that is always finite. Our results are compatible with various experimental trends, including the onset of longer range correlations induced by interlayer coupling above a characteristic field scale.