Fragile superconductivity in the presence of weakly disordered charge density waves

TL;DR

This paper uses Landau-Ginzberg-Wilson theory to show that weak disorder can induce a fragile superconducting phase near charge-density wave dislocations, explaining recent high-field superconductivity observations.

Contribution

It introduces a theoretical framework demonstrating the emergence of a fragile SC phase due to weak disorder and CDW dislocations, linking to experimental high-field superconductivity.

Findings

Fragile SC phase appears at low temperatures and high fields with weak disorder.

Superconductivity is concentrated near CDW dislocations, with reduced transition temperatures.

Potential explanation for resilient high-field superconductivity in underdoped cuprates.

Abstract

When superconducting (SC) and charge-density wave (CDW) orders compete, novel low temperature behaviors can result. From an analysis of the Landau-Ginzberg-Wilson theory of competing orders, we demonstrate the generic occurrence of a `fragile' SC phase at low temperatures and high fields in the presence of weak disorder. Here, the SC order is largely concentrated in the vicinity of dilute dislocations in the CDW order, leading to transition temperatures and critical currents that are parametrically smaller than those characterizing the zero field SC phase. This may provide the outline of an explanation of the recently discovered `resilient' superconducting phase at high fields in underdoped YBa$_2$Cu$_3$O$_{6+\delta}$.