Superconductivity in the charge-density-wave state of the organic metal \alpha-(BEDT-TTF)2KHg(SCN)4

TL;DR

This study investigates how superconductivity coexists with charge-density waves in an organic metal, revealing weakly coupled superconducting regions and enhanced critical fields within the density-wave state.

Contribution

It provides new insights into the interplay between superconductivity and charge-density waves in layered organic compounds under different pressure regimes.

Findings

Superconductivity exists within the charge-density-wave state with weakly coupled regions.

Enhanced critical magnetic fields are observed in the density-wave state.

Superconducting traces appear at higher temperatures when pressure lowers into the density-wave regime.

Abstract

The superconducting transition in the layered organic compound \alpha-(BEDT-TTF)_2KHg(SCN)_4 has been studied in the two hydrostatic pressure regimes where a charge-density wave is either present or completely suppressed. Within the charge-density-wave state the experimental results reveal a network of weakly coupled superconducting regions. This is especially seen in a strong enhancement of the measured critical field and the corresponding positive curvature of its temperature dependence. Further, it is shown that on lowering the pressure into the density-wave state traces of a superconducting phase already start to appear at a much higher temperature.