Gate-Induced Mott Transition

TL;DR

This paper demonstrates a gate-induced Mott transition in VO2, showing an abrupt, digital-like change in conductivity that suggests potential for high-speed switching transistors based on strongly correlated materials.

Contribution

It reports the first observation of a gate-induced Mott transition in VO2, revealing a discontinuous, digital gate effect linked to the material's proximity to the critical Coulomb energy.

Findings

Abrupt Mott MIT observed near U/Uc=1

Gate effect causes large conductivity change

Discontinuous, digital-like gate response

Abstract

For a strongly correlated material, VO2, near a critical on-site Coulomb energy U/Uc=1, the abrupt Mott metal-insulator transition (MIT) rather than the continuous Hubbard MIT is observed by inducing internal optical phonon-coupled holes (hole inducing of 0.018%) into conduction band, with a gate field of fabricated transistors. Observed gate effects, change of the MIT drain-source voltage caused by a gate field, are the effect of measurement due to inhomogeneity of channel material and is an average over the measurement region of the true gate effect based on the large conductivity (or effective mass) near the MIT predicted by the Brinkman-Rice picture. A discontinuous gate effect such as digital is observed, which is a characteristic of the transistor and a possible condition of a very high-speed switching transistor.