Bad metallic transport in geometrically frustrated models

TL;DR

This paper investigates how geometrically frustrated models on a triangular lattice exhibit bad metallic behavior with high resistivity and linear temperature dependence, transitioning to insulators at certain fillings.

Contribution

It provides an exact solution in the interaction-only limit and analyzes transport properties at finite hopping, revealing novel bad-metallic regimes and insulator transitions.

Findings

Resistivity scales linearly with temperature over broad ranges.

Resistivity values exceed the quantum of resistance $h/e^2$.

Insulating phases emerge at specific fillings at low temperatures.

Abstract

We study the transport properties for a family of geometrically frustrated models on the triangular lattice with an interaction scale far exceeding the single-particle bandwidth. Starting from the interaction-only limit, which can be solved exactly, we analyze the transport and thermodynamic behavior as a function of filling and temperature at the leading non-trivial order in the single-particle hopping. Over a broad range of intermediate temperatures, we find evidence of a dc resistivity scaling linearly with temperature and with typical values far exceeding the quantum of resistance, $h/e^2$. At a sequence of commensurate fillings, the bad-metallic regime eventually crosses over into interaction induced insulating phases in the limit of low temperatures. We discuss the relevance of our results to experiments in cold-atom and moir\'e heterostructure based platforms.