Fermi surface instabilities at finite Temperature

TL;DR

The paper introduces a new analytical method to detect Fermi surface instabilities at finite temperature, successfully reproducing known results and providing insights into phase diagrams and non-Fermi Liquid behavior.

Contribution

A novel method for detecting Fermi surface instabilities at finite temperature, enabling analytical phase diagram analysis and application to complex materials.

Findings

Recovered known phase diagram results efficiently

Derived critical temperature as a function of magnetic field and chemical potential

Identified non-Fermi Liquid region above the nematic phase in a model for Sr3Ru2O7

Abstract

We present a new method to detect Fermi surface instabilities for interacting systems at finite temperature. We first apply it to a list of cases studied previously, recovering already known results in a very economic way, and obtaining most of the information on the phase diagram analytically. As an example, in the continuum limit we obtain the critical temperature as an implicit function of the magnetic field and the chemical potential $T_c(\mu,h)$. By applying the method to a model proposed to describe reentrant behavior in $Sr_3Ru_2O_7$, we reproduce the phase diagram obtained experimentally and show the presence of a non-Fermi Liquid region at temperatures above the nematic phase.