Self-localization of composite spin-lattice polarons

TL;DR

This paper investigates how holes self-localize in the Holstein t-J model, revealing that increased magnetic interactions lower the electron-phonon coupling needed for localization, with implications for lightly doped cuprates.

Contribution

It provides a detailed analysis of hole self-localization mechanisms in the Holstein t-J model, emphasizing the role of incoherent motion and magnetic correlations.

Findings

Critical electron-phonon coupling decreases with increasing J.

Incoherent hole motion primarily influences localization.

Antiferromagnetic order persists up to significant hole doping.

Abstract

Self-localization of holes in the Holstein t-J model is studied in the adiabatic limit using exact diagonalization and the retraceable path approximation. It is shown that the critical electron-phonon coupling \lambda_c decreases with increasing J and that this behavior is determined mainly by the incoherent rather than by the coherent motion of the hole. The obtained spin correlation functions in the localized region can be understood within a percolation picture where antiferromagnetic order can persist up to a substantial hole doping. These results restrict the possibility of self-localization of holes in lightly doped cuprates.