Phase diagram of t-t' Hubbard model taking into account spin-spiral waves and phase separation at finite temperature

TL;DR

This study investigates how temperature influences magnetic phase separation and spin-spiral wave parameters in a 2D t-t' Hubbard model, revealing significant temperature-dependent changes in magnetic phases and phase separation regions relevant to cuprates.

Contribution

It provides a detailed analysis of temperature effects on magnetic phases and phase separation in the t-t' Hubbard model, incorporating spin-spiral waves and phase separation at finite temperatures.

Findings

Phase separation regions decrease with increasing temperature.

New magnetic phases emerge at higher temperatures.

Results aid in understanding magnetic properties of cuprates.

Abstract

The effect of temperature on the magnetic phase separation and the parameters of spin-spiral waves (SSW) is studied using a two-dimensional (2D) single-band $t-t'$ Hubbard model and the Hubbard-Stratonovich transformation. Both commensurate (antiferromagnetic (AF)) and incommensurate (helical) magnetic phases are considered. It is shown that the temperature significantly affects the collinear and helical magnetic phases. With an increase in the temperature, the phase-separation (PS) regions (AF$+[Q,Q])$, $([Q,Q]+[Q,\pi])$ get substantially reduced but new regions $([Q_{1},\pi]+[Q_{2},\pi])$, (AF$+[Q,\pi])$ arise. The results are used for the interpretation of the magnetic properties of cuprates.