Chasing the spin gap through the phase diagram of a frustrated Mott insulator

Abstract

The Mott insulator κ-(BEDT-TTF)2Cu2(CN)3 has been a strong candidate for a gapless quantum spin liquid, but recent experiments suggested a spin-gapped phase below 6 K. Pustogow et al. study the entropy of this phase by driving the system through the metal-insulator transition with a strain engineering approach.