Two interacting current model of holographic Dirac fluid in graphene

TL;DR

This paper models the transport properties of graphene near the Dirac point using holography, incorporating current interactions and magnetic fields, and explores the influence of a dark matter sector on these properties.

Contribution

It extends previous holographic models by including current interactions and magnetic fields, and interprets one current as arising from dark matter, providing new insights into graphene's transport behavior.

Findings

Transport parameters are significantly affected by magnetic fields.

The model's Seebeck coefficient matches experimental data.

Dark matter sector influences are mostly quantitative, complicating detection.

Abstract

The electrons in graphene for energies close to the Dirac point have been found to form strongly interacting fluid. Taking this fact into account we have extended previous work on the transport properties of graphene by taking into account possible interactions between the currents and adding the external magnetic field directed perpendicularly to the graphene sheet. The perpendicular mag- netic field B severely modifies the transport parameters. In the present approach the quantization of the spectrum and formation of Landau levels is ignored. Gauge/gravity duality has been used in the probe limit. The dependence on the charge density of the Seebeck coefficient and thermo-electric parameters {\alpha}ij nicely agree with recent experimental data for graphene. The holographic model allows for the interpretation of one of the fields representing the currents as resulting from the dark matter sector. For the studied geometry with electric field perpendicular to the thermal gradient the effect of dark sector has been found to modify the transport parameters but mostly in a quantitative way only. This makes difficult the detection of this elusive component of the Universe by studying transport properties of graphene.