Determination of Dynamical exponents of Graphene at quantum critical point by holography

TL;DR

This paper uses holographic methods to analyze transport in a theory with two conserved currents, fitting graphene data to determine its quantum critical point exponents, finding that (z,θ)=(3/2,1) provides a better match than (1,0).

Contribution

It introduces a holographic approach to determine the dynamical exponents of graphene at its quantum critical point, emphasizing the significance of (z,θ)=(3/2,1) for better data fitting.

Findings

Electric and thermal conductivities fit better with (z,θ)=(3/2,1).

Thermoelectric power data at high temperature fit with (3/2,1).

The results suggest fermionic nature and strong interactions influence the exponents.

Abstract

We calculate the transport of a theory with two conserved currents by holographic method and compare it with graphene data to determine its dynamical exponents $(z,\theta)$ which characterizes a QCP. As a result, we find that the electric and the thermal conductivity data can be fit much more naturally if we assume $(z,\theta)=(3/2,1)$ rather than $(1,0)$. Furthermore, we find that thermoelectric power data at high temperature can be fit if we use $(3/2,1)$ but not at all by $(1,0)$. The $\theta=1$ result can be interpreted as taking into account the fermionic nature of the electrons and $z=3/2$ can be interpreted as the flattened band by the strong interaction.