Temperature dependent resistivity in the doped two dimensional metallic phase of mTMD bilayers

TL;DR

This paper explains the temperature-dependent resistivity in doped 2D moiré transition metal dichalcogenides by linking it to Friedel oscillations and Coulomb disorder, highlighting the role of temperature-dependent screening.

Contribution

It introduces a theory connecting temperature-dependent resistivity in doped 2D mTMDs to Friedel oscillations and Coulomb disorder, advancing understanding of metallic phases away from half-filling.

Findings

Resistivity increases linearly with temperature in the metallic phase.

Temperature-dependent screening explains the resistivity behavior.

Theory accounts for experimental observations in doped mTMDs.

Abstract

Two recent experiments from Cornell and Columbia have reported insulator-to-metal transitions in two-dimensional (2D) moir\'e transition metal dichalcogenides (mTMD) induced by doping around half-filling, where the system is a Mott insulator. In the current work, we consider the temperature dependent resistivity of this metallic phase in the doped situation away from half-filling, arguing that it arises from the strongly temperature dependent 2D Friedel oscillations (i.e. finite momentum screening) associated with random quenched charged impurities, leading to the observed strongly increasing linear-in-$T$ resistivity in the metallic phase. Our theory appears to account for the temperature-dependent metallic resistivity for doping around half-filling of the effective moir\'e TMD band, showing that temperature-dependent screened Coulomb disorder is an essential ingredient of doped 2D mTMD physics.