Hydrostatic-Pressure-Induced Reentrance of the Metallic State in the κ-(ET) 2 Hg(SCN) 2 Cl Quasi-Two-Dimensional Organic Conductor

On cooling below 30 K, the κ-(ET)2Hg(SCN)2Cl quasi-two-dimensional organic metal, which is in the quantum spin liquid state at liquid helium temperatures, undergoes a transition to the Mott insulator state. The application of a hydrostatic pressure p = 0.7 kbar stabilizes the metallic state and makes it possible to study the behavior of the interlayer magnetoresistance at liquid helium temperatures. The field dependence of the magnetoresistance exhibits an unlimited power-law growth, which indicates that the polaron mechanism contributes to the interlayer transport. The spectrum of observed magnetoresistance oscillations corresponds to the Fermi surfaces characteristic of conducting layers with the κ-type structure.