Temperature and doping dependence of high-energy kink in cuprates

TL;DR

This study uses the extended t-J model to analyze the high-energy kink in cuprates, showing it persists across doping levels and temperatures in hole-doped but not in electron-doped cuprates, highlighting strong correlation effects.

Contribution

It demonstrates that the high-energy kink and waterfall features are due to strong correlations and incoherent hole propagation, consistent with experimental ARPES data, and predicts their absence in electron-doped cuprates.

Findings

High-energy kink persists in hole-doped cuprates up to large doping and high temperatures.

Waterfall features are linked to strong correlations and incoherent hole motion.

Electron-doped cuprates do not show these phenomena in photoemission.

Abstract

It is shown that spectral functions within the extended t-J model, evaluated using the finite-temperature diagonalization of small clusters, exhibit the high-energy kink in single-particle dispersion consistent with recent angle-resolved photoemission results on hole-doped cuprates. The kink and waterfall-like features persist up to large doping and to temperatures beyond $J$ hence the origin can be generally attributed to strong correlations and incoherent hole propagation at large binding energies. In contrast, our analysis predicts that electron-doped cuprates do not exhibit these phenomena in photoemission.