Direct evidence for superconductivity in the organic charge density-wave compound alpha-(BEDT-TTF)_2KHg(SCN)_4 under hydrostatic pressure

TL;DR

This study provides direct evidence of superconductivity in the organic compound alpha-(BEDT-TTF)_2KHg(SCN)_4 under hydrostatic pressure, with the transition persisting across a range of pressures and changing character as charge-density wave order is suppressed.

Contribution

The paper reports the first direct observation of superconductivity in this specific organic compound under pressure, highlighting the relationship between charge-density wave suppression and superconducting transition.

Findings

Superconductivity observed below 300 mK under 0-4 kbar pressure.

Superconducting transition persists across the entire pressure range studied.

Transition character changes as charge-density wave state is suppressed.

Abstract

We present direct evidence of a superconducting state existing in the title compound below 300 mK under quasi-hydrostatic pressure. The superconducing transition is observed in the whole pressure range studied, 0 < P < 4 kbar. However, the character of the transition drastically changes with suppressing the charge-density wave state.