Strange metal transport from coupling to fluctuating spins

TL;DR

This study uses advanced numerical methods to analyze the conductivity of the 2D t-J model, revealing that strange metallic behavior is linked to suppressed antiferromagnetic order and rooted in quantum statistical effects rather than carrier scattering.

Contribution

The paper provides the first numerically exact calculations at low temperatures for the 2D t-J model, connecting strange metal behavior to quantum statistical origins.

Findings

Strange metallicity is common when antiferromagnetic order is suppressed.

Planckian relaxation is better understood through frequency and time domain analysis.

The quantum statistical nature of charge response underpins strange metal behavior.

Abstract

Metals hosting strong electronic interactions, including high-temperature superconductors, behave in ways that do not conform to normal Fermi liquid theory. To pinpoint the microscopic origin of this strange metal behavior, here we reexamine the d.c. and frequency-dependent conductivity of the two-dimensional t-J model taking advantage of recent improvements made on the finite temperature Lanczos method, enabling numerically exact calculations at unprecedentedly low temperatures and high spectral resolution. We find that strange metallicity is pervasive in the temperature-doping phase diagram whenever anti-ferromagnetic order is suppressed, and advocate that key insights on Planckian relaxation can be gained by extending the study to the frequency and time domain. Our results indicate that Planckian behavior does not originate from the scattering properties of the current carriers, being instead rooted in the quantum statistical nature of the charge response.