FisMat2017 - Submission - View

Abstract's title: FIELD-DRIVEN MOTT GAP COLLAPSE AND RESISTIVE SWITCH IN CORRELATED INSULATORS
Submitting author: Adriano Amaricci
Affiliation: SISSA
Affiliation Address: via Bonomea 265, 34126 Trieste
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Giacomo Mazza (CPhT, Ecole Polytechnique and College de France, Paris), Massimo Capone (SISSA, Trieste), Michele Fabrizio (SISSA, Trieste)
Abstract

The electric field-driven formation of conductive states in an otherwise insulating system is a key phenomenon in the electronic devices engineering.

Unlike semiconductors, Mott insulators are “unsuccessful metals”  in which a strong Coulomb repulsion prevents charge conduction despite a metal-like concentration of conduction electrons. Therefore, the possibility to unlock such large density of frozen carriers with an electric field offers  tantalizing prospects of realizing new Mott-based electronic devices in which the number of carriers is not bounded by the size of the gap and the strength of the field, a key issue in devices miniaturization trend [1].

In this talk I will discuss a theoretical description which explicitly unveils how such unlocking happens considering a simple model for correlated insulators [2]. 

Specifically, I will show that close to an equilibrium Mott transition the electric breakdown of the Mott insulator can occur via a first-order insulator-to-metal transition characterized by an abrupt gap-collapse at threshold fields much smaller than those expected in a Zener breakdown. This is the result of the stabilization of a metallic phase that preexists as metastable state in equilibrium and is disconnected from the stable insulator.

The relevance of these findings in relation with recent observations in resistive switch experiments in several Mott insulators [3,4]  will be discussed. 

References:

[1] I. H. Inoue and M. J. Rozenberg Advanced Functional Materials 18, 2289-2292, (2008)

[2] G. Mazza, A. Amaricci, M. Capone and M. Fabrizio Phys. Rev. Lett. 117, 176401 (2016)

[3] V. Guiot et al. Nature Communications, 4, 1722 (2013)

[4] E. Janod et al. Advanced Functional Materials, 25, 6287–6305 (2015)