Thermoelectric Transport in Holographic Quantum Matter under Shear Strain

TL;DR

This paper investigates how shear strain influences thermoelectric transport in two-dimensional quantum matter using holographic duality, revealing strain-induced metal-insulator transitions and violations of thermal conductivity bounds.

Contribution

It provides the first analytic formulas for DC thermoelectric conductivities under shear strain in holographic models and explores their effects on transport properties and phase transitions.

Findings

Shear strain induces metal-insulator transitions.

Shear deformation can violate thermal conductivity bounds.

Electric conductivity behavior is strongly affected by strain.

Abstract

We study the thermoelectric transport under shear strain in two spatial dimensional quantum matter using the holographic duality. General analytic formulae for the DC thermoelectric conductivities subjected to finite shear strain are obtained in terms of the black hole horizon data. Off-diagonal terms in the conductivity matrix appear also at zero magnetic field, resembling an emergent electronic nematicity which cannot nevertheless be identified with the presence of an anomalous Hall effect. For an explicit model study, we numerically construct a family of strained black holes and obtain the corresponding nonlinear stress-strain curves. We then compute all electric, thermoelectric, and thermal conductivities and discuss the effects of strain. While the shear elastic deformation does not affect the temperature dependence of thermoelectric and thermal conductivities quantitatively, it can strongly change the behavior of the electric conductivity. For both shear hardening and softening cases, we find a clear metal-insulator transition driven by the shear deformation. Moreover, the violation of the previously conjectured thermal conductivity bound is observed for large shear deformation.