# Protected superconductivity at the boundaries of charge-density-wave domains

## TL;DR

This paper demonstrates that in disordered systems with competing charge-density-waves and superconductivity, topologically protected filamentary superconductivity emerges at domain boundaries, supported by experimental and theoretical evidence.

## Contribution

It reveals the formation of protected filamentary superconductivity at CDW domain boundaries in disordered materials, linking experimental observations with theoretical models.

## Key findings

- Transition from CDWs to fluctuating superconductivity at high temperature and low fields.
- Emergence of protected filamentary superconductivity at high fields and low temperatures.
- Agreement between transport experiments in cuprates and theoretical predictions.

## Abstract

Solid 4He may acquire superfluid characteristics due to the frustration of the solid phase at grain boundaries. Here, we show that an analogous effect occurs in systems with competition among charge-density-waves (CDWs) and superconductivity in the presence of disorder, as cuprate or dichalcogenide superconductors. The CDWs breaks apart in domains with topologically protected filamentary superconductivity (FSC) at the interfaces. Transport experiments carried out in underdoped cuprates with the magnetic field acting as a control parameter are shown to be in excellent agreement with the theoretical expectation. At high temperature and low fields we find a transition from CDWs to fluctuating superconductivity, weakly affected by disorder, while at high field and low temperature the protected filamentary superconducting phase appears in close analogy with "glassy" supersolid phenomena in 4He.