Strange metal behavior from incoherent carriers scattered by local moments

TL;DR

This paper models metallic transport near the Mott transition, showing that scattering by fluctuating local moments leads to incoherent, strange metal behavior with linear temperature-dependent resistivity and universal characteristics.

Contribution

It introduces a new effective model capturing strange metal behavior through local moment fluctuations without relying on quantum criticality or quasiparticles.

Findings

Incoherent electron transport with linear T resistivity.

Universal 'Planckian' slope and finite T=0 intercept.

Strange metal behavior arises from local moment fluctuations.

Abstract

We study metallic transport in an effective model that describes the coupling of electrons to fluctuating magnetic moments with full SU(2) symmetry, exhibiting characteristic behavior of metals at the approach of the Mott transition. We show that scattering by fluctuating local moments causes a fully incoherent regime of electron transport with linear T-dependent resistivities. This strange metal regime is characterized by almost universal, "Planckian" slope and a finite intercept at $T=0$, that we can associate respectively to the fluctuations in orientation and amplitude of the local moments. Our results indicate a route for understanding the microscopic origin of strange metal behavior that is unrelated to quantum criticality and does not rely on the existence of quasiparticles.