Evolution of photoemission spectral functions in doped transition metal oxides

TL;DR

This paper investigates how photoemission spectral functions evolve in doped transition metal oxides, emphasizing the importance of spatial inhomogeneities and surface-bulk differences for understanding experimental data.

Contribution

It introduces a theoretical approach to model spectral function evolution considering inhomogeneities, advancing the understanding of correlated electron systems in transition metal oxides.

Findings

Spectral functions vary with inhomogeneity levels.

Surface regions exhibit stronger correlations and disorder.

Comparison with experiments requires accounting for surface-bulk differences.

Abstract

We discuss the experimental photoemission and inverse photoemission of early transition metal oxides, in the light of the dynamical mean field theory of correlated electrons which becomes exact in the limit of infinite dimensions. We argue that a comprehensive description of the experimental data requires spatial inhomogeneities and present a calculation of the evolution of the spectral function in an inhomogenous system with various degrees of inhomogeneity. We also point out that comparaison of experimental results and large d calculations require that the degree of correlation and disorder is larger in the surface than in the bulk.