Physics of interface: Mott insulator barrier sandwiched between two metallic planes

TL;DR

This paper investigates a heterostructure with a Mott insulator barrier between metallic planes, revealing a transition to a Mott insulator at high correlation and a complex energy spectrum with multiple gaps.

Contribution

It introduces a detailed analysis of the electronic properties of a metal-Mott insulator-metal heterostructure using unrestricted Hartree Fock, highlighting novel spectral features.

Findings

System becomes a Mott insulator above a critical correlation strength.

System remains non-metallic for all finite correlations.

Energy spectrum exhibits multiple gaps.

Abstract

We consider a heterostructure of a metal and a barrier with onsite correlation at half filling using unrestricted Hartree Fock. We find that above a certain value of correlation strength in the barrier planes, the system is a Mott insulator, while below this value the system still behaves like a gapless insulator. The energy spectrum is found to be very novel with the presence of multiple gaps. Thus the system remains non metallic for any finite value of correlation.