Magnetic Properties of the t-J Model in the Dynamical Mean-Field Theory

TL;DR

This paper develops a dynamical mean-field theory approach to analyze the magnetic properties of the t-J model, providing insights into spin correlations and phase diagrams relevant for strongly correlated electron systems.

Contribution

It introduces a new DMFT-based method to compute spin correlations in the t-J model, bridging local and non-local susceptibilities with a systematic comparison to the Hubbard model.

Findings

Calculated magnetic susceptibility shows qualitative agreement with known results.

Identified key differences between t-J and Hubbard models at large U.

Mapped the magnetic phase diagram of the t-J model.

Abstract

We present a theory for the spin correlation function of the t-J model in the framework of the dynamical mean-field theory. Using this mapping between the lattice and a local model we are able to obtain an intuitive expression for the non-local spin susceptibility, with the corresponding local correlation function as input. The latter is calculated by means of local Goldstone diagrams following closely the procedures developed and successfully applied for the (single impurity) Anderson model.We present a systematic study of the magnetic susceptibility and compare our results with those of a Hubbard model at large U. Similarities and differences are pointed out and the magnetic phase diagram of the t-J model is discussed.