First-Order Insulator-to-Metal Mott Transition in the Paramagnetic 3D System GaTa4Se8

TL;DR

This study investigates the first-order insulator-to-metal Mott transition in the 3D system GaTa4Se8, revealing coexistence of insulating and metallic states and supporting findings with advanced theoretical calculations.

Contribution

It provides the first experimental evidence of a first-order Mott transition in a 3D system without symmetry breaking, supported by LDA+DMFT calculations.

Findings

Transition is of first order with coexistence of states

Transition can be toggled with small bias current

Experimental results agree with LDA+DMFT calculations

Abstract

The nature of the Mott transition in the absence of any symmetry braking remains a matter of debate. We study the correlation-driven insulator-to-metal transition in the prototypical 3D Mott system GaTa4Se8, as a function of temperature and applied pressure. We report novel experiments on single crystals, which demonstrate that the transition is of first order and follows from the coexistence of two states, one insulating and one metallic, that we toggle with a small bias current. We provide support for our findings by contrasting the experimental data with calculations that combine local density approximation with dynamical mean-field theory, which are in very good agreement.