Pressure tuning of localization and superconductivity in LaOPbBiS$_{3}$ and La$_{2}$O$_{2}$Bi$_{3}$AgS$_{6}$

TL;DR

This study investigates how applying pressure affects electrical transport and induces superconductivity in two layered bismuth chalcogenides, revealing disorder's role in enhancing superconductivity near localization thresholds.

Contribution

It demonstrates pressure-induced superconductivity in LaOPbBiS$_{3}$ and La$_{2}$O$_{2}$Bi$_{3}$AgS$_{6}$ and explores the disorder-superconductivity relationship in these materials.

Findings

Pressure suppresses semiconducting behavior and induces superconductivity.

Superconductivity enhancement is linked to disorder near localization threshold.

Phase diagrams differ from charge density wave interactions, highlighting disorder effects.

Abstract

We report the effect of pressure on the electrical transport properties of the four-layer-type bismuth chalcogenide semiconductors LaOPbBiS$_{3}$ and La$_{2}$O$_{2}$Bi$_{3}$AgS$_{6}$ and present the discovery of a pressure-induced superconductivity. In both compounds, the semiconductorlike behavior concomitant with an anomaly in the more insulating state is gradually suppressed with increasing pressure while the superconductivity develops. The obtained phase diagrams, in sharp contrast with the interplay between the conventional charge density waves and superconductivity, suggest that the enhancement of the superconductivity is due to the disorder near the localization threshold. These results indicate that pressure tuning of the local disorder in four-layer-type bismuth chalcogenides provides an attractive opportunity to study the interplay between disorder and superconductivity.