Inverse photoemission in strongly correlated electron systems

TL;DR

This paper uses exact calculations on small 2D t-J model clusters to reveal multiple channels in inverse photoemission spectra, showing complex quasiparticle behavior consistent with experimental observations in cuprates.

Contribution

It demonstrates the existence of distinct inverse photoemission channels and their implications for understanding Fermiology in strongly correlated electron systems.

Findings

Multiple inverse photoemission channels identified

Spectral weight distribution resembles free electrons despite hole pockets

Results align with experimental data on cuprate superconductors

Abstract

Based on exact results for small clusters of 2D t-J model we demonstrate the existence of several distinct `channels' in its inverse photoemission (IPES) spectrum. Hole-like quasiparticles can either be annihilated completely, or leave behind a variable number of spin excitations, which formed the `dressing cloud' of the annihilated hole. In the physical parameter regime the latter processes carry the bulk of IPES weight and although the Fermi surface takes the form of hole pockets, the distribution of spectal weight including these `magnon-bands' in the IPES spectrum is reminiscent of free electrons. The emerging scenario for Fermiology and spectral weight distribution is shown to be consistent with photoemission, inverse photemission and de Haas--van Alphen experiments on cuprate superconductors.