Magnetotransport from the fluid/gravity correspondence

TL;DR

This work develops a magnetohydrodynamic description for a holographic model with broken translational invariance by applying the fluid/gravity correspondence to a 4D Einstein-Maxwell-Dilaton theory with momentum-relaxing scalars and an external magnetic field. The authors derive constitutive relations and a Ward identity in a derivative expansion, then linearize to obtain low-frequency thermoelectric coefficients, revealing subleading corrections to the Nernst-like behavior and a Drude-like pole structure governed by $\tau^{-1}$, $\omega_c$, and $\gamma$. They show that the DC limit can be captured exactly by a horizon-fluid approach (Donos-Gauntlett) and provide a DC hydrodynamic reformulation that yields closed-form expressions for all relevant conductivities, consistent with EM duality. The results offer a concrete, holographically controlled framework for non-Drude magnetotransport in systems with momentum relaxation, with potential relevance to strange metal phenomenology and related experimental observations.

Abstract

We continue our construction of a hydrodynamical description of a holographic model with broken translation invariance. Using the fluid/gravity correspondence we derive the constitutive relations of the boundary theory in the presence of a magnetic field. This allows us to obtain novel results for the low-frequency magnetothermoelectric response coefficients. We discuss the DC limit of our hydrodynamics in detail, and show that our approach is equivalent to the `horizon-fluid' of Donos and Gauntlett.