Filling of the Mott-Hubbard gap in the high temperature photoemission spectrum of (V_0.972Cr_0.028)_2O_3

TL;DR

This study investigates the high-temperature photoemission spectra of a Mott-Hubbard insulator, revealing the filling of the gap with spectral weight transfer up to 800 K, aligning with advanced theoretical predictions.

Contribution

It provides experimental evidence of Mott-Hubbard gap filling at high temperatures, confirming theoretical models combining dynamical mean field theory and band theory.

Findings

Mott-Hubbard gap is filled at high temperatures

Spectral weight transfer observed up to 800 K

Results agree with advanced theoretical calculations

Abstract

Photoemission spectra of the paramagnetic insulating (PI) phase of (V_0.972Cr_0.028)_2O_3, taken in ultra high vacuum up to the unusually high temperature (T) of 800 K, reveal a property unique to the Mott-Hubbard (MH) insulator and not observed previously. With increasing T the MH gap is filled by spectral weight transfer, in qualitative agreement with high-T theoretical calculations combining dynamical mean field theory and band theory in the local density approximation.