Character of Matter in Holography: Spin-Orbit Interaction

TL;DR

This paper explores how spin-orbit interactions in matter can be understood through holography by lifting them to axionic couplings in the bulk, providing analytic solutions and connecting with experimental data.

Contribution

It introduces a systematic method to characterize matter in holography by lifting spin-orbit interactions to axionic couplings, with exact solutions and experimental relevance.

Findings

Exact analytic solution for diamagnetic response

DC transport coefficients with interpolating Hall coefficient

Experimental similarity with annealed graphite data

Abstract

Gauge/Gravity duality as a theory of matter needs a systematic way to characterise a system. We suggest a `dimensional lifting' of the least irrelevant interaction to the bulk theory. As an example, we consider the spin-orbit interaction, which causes magneto-electric interaction term. We show that its lifting is an axionic coupling. We present an exact and analytic solution describing diamagnetic response. Experimental data on annealed graphite shows a remarkable similarity to our theoretical result. We also find an analytic formulas of DC transport coefficients, according to which, the anomalous Hall coefficient interpolates between the coherent metallic regime with $\rho_{xx}^{2}$ and incoherent metallic regime with $\rho_{xx}$ as we increase the disorder parameter $\beta$. The strength of the spin-orbit interaction also interpolates between the two scaling regimes.