Nematic phases and elastoresistivity from a multiorbital non-Fermi liquid

TL;DR

This paper introduces a two-orbital Sachdev-Ye-Kitaev model extension that reveals a rich phase diagram with nematic phases, and analyzes their spectral and transport properties, including elastoresistivity.

Contribution

It presents a novel multiorbital lattice model extending the SYK framework, demonstrating nematic phase transitions and their impact on transport in correlated systems.

Findings

Identification of a first-order transition to nematic insulator

Observation of a peak in elastoresistivity near the nematic transition

Spectral and transport properties characteristic of nematic phases

Abstract

We propose and study a two-orbital lattice extension of the Sachdev-Ye-Kitaev model in the large-$N$ limit. The phase diagram of this model features a high temperature isotropic strange metal which undergoes a first-order thermal transition into a nematic insulator or a continuous thermal transition into nematic metal phase, separated by a tunable tricritical point. These phases arise from spontaneous partial orbital polarization of the multiorbital non-Fermi liquid. We explore the spectral and transport properties of this model, including the d.c. elastoresistivity, which exhibits a peak near the nematic transition, as well as the nonzero frequency elastoconductivity. Our work offers a useful perspective on nematic phases and transport in correlated multiorbital systems.