Quantum-critical resistivity of strange metals in a magnetic field

TL;DR

This paper extends a theory of linear temperature resistivity in strange metals to include magnetic field effects, predicting a linear-in-H resistivity due to vortex scattering in quantum-critical regimes.

Contribution

It introduces a model where magnetic vortices in loop-current fluctuations cause linear-in-H resistivity, linking magnetic field response to quantum-critical fluctuations.

Findings

Resistivity is linear in magnetic field $H_z$ due to vortex scattering.

The $H_z$-linear resistivity coefficient scales with the marginal Fermi-liquid susceptibility.

Quantitative agreement with experimental data on various strange metals is demonstrated.

Abstract

Resistivity in the quantum-critical fluctuation region of several metallic compounds such as the cuprates, the heavy-fermions, Fe-chalogenides and pnictides, twisted bi-layer graphene and WSe$_2$, is linear in temperature $T$ as well as in a magnetic field $H$. Scattering of fermions by the excitations of a time-reversal odd polar vector field ${\bf \Omega}$ characterizing loop-current fluctuations has been shown to give a linear in T resistivity and other anomalous properties in the cuprates. An extension of this theory to an applied magnetic field is presented. Magnetic field is shown to generate vortices in the field ${\bf \Omega}$ proportional to $H_z$, the component orthogonal to the conducting planes. The elastic scattering of fermions from the vortices gives a resistivity linear in $H_z$. The coefficient of the linear in $H_z$ resistivity is predicted to vary as the marginal fermi-liquid susceptibility $\propto \ln(\frac{\omega_c}{T})$ at criticality. Quantitative comparison with experiments is presented.