Superconductivity, incoherence and Anderson localization in the crystalline organic conductor (BEDT-TTF)_3Cl_2.2H_2O at high pressures

TL;DR

This study investigates the high-pressure superconducting organic conductor (BEDT-TTF)_3Cl_2.2H_2O, revealing layered incoherent transport, strong upper critical fields, and Anderson localization effects that are suppressed with increased pressure.

Contribution

It provides new insights into the interplay of superconductivity, incoherence, and localization phenomena in layered organic conductors under high pressure.

Findings

Upper critical field exceeds Pauli limit when field is parallel to layers

Incoherent interlayer transport indicated by angle-dependent magnetoresistance

Anderson localization explains negative magnetoresistance at 13.5 kbar

Abstract

The conducting properties of the pressure-induced, layered organic superconductor (BEDT-TTF)_3Cl_2.2H_20 have been studied at 13.5 and 14.0 kbar using low temperatures, high magnetic fields and two-axis rotation. An upper critical field that is significantly larger than that expected from the Pauli paramagnetic limit is observed when the field is applied parallel to the conducting layers. The angle dependent magnetoresistance suggests incoherent transport between the conducting layers at both pressures and the observed negative magnetoresistance at 13.5 kbar can be explained by considering Anderson localization within the layers. Further application of pressure destroys the effects of localization.