Memory matrix theory of magnetotransport in strange metals

TL;DR

This work develops a memory-matrix framework to model magnetotransport in strange metals lacking quasiparticles but with slow momentum relaxation and diffusive charge/energy dynamics. By systematically incorporating both momentum relaxation and diffusion, the authors derive general expressions for electrical, thermal, and thermoelectric transport in a magnetic field, unifying hydrodynamic and holographic perspectives and clarifying connections to cuprate experiments. The key contribution is a tractable, microscopic route to compute transport coefficients from slow modes, yielding explicit results for σ_ij, α_ij, and κ̄_ij that reduce to known limits and remain valid beyond strict hydrodynamics. This provides a bridge between microscopic models of strange metals and macroscopic transport observables, with implications for analyzing cuprate data and guiding microscopically realistic calculations.

Abstract

We model strange metals as quantum liquids without quasiparticle excitations, but with slow momentum relaxation, and with slow diffusive dynamics of a conserved charge and energy. General expressions are obtained for electrical, thermal and thermoelectric transport in the presence of an applied magnetic field using the memory matrix formalism. In the appropriate limits, our expressions agree with previous hydrodynamic and holographic results. We discuss the relationship of such results to thermoelectric and Hall transport measurements in the strange metal phase of the hole-doped cuprates.

Figures (1)

• Figure 1: An illustration of the connections between hydrodynamics, memory matrices, and holography.