Holography of the Dirac Fluid in Graphene with Two Currents
Recent experiments have uncovered evidence of the strongly coupled nature of graphene: the Wiedemann-Franz law is violated by up to a factor of 20 near the charge neutral point. Profs. Philip Kim and Subir Sachdev and colleagues from Hanyang University, Seoul, described this strongly coupled plasma in a recent article in PRL. Their description uses a holographic model in which there are two distinct conserved U(1) currents. The authors found find that their analytic results for the transport coefficients for the two current model have a significantly improved match to the density dependence of the experimental data than the models with only one current. The article also suggests the origin of the two currents.
See Y. Seo, G. Song, P. Kim, S. Sachdev, and S.-J. Sin, "Holography of the Dirac Fluid in Graphene with Two Currents," Phys. Rev. Lett. 118, 036601 DOI: https://doi.org/10.1103/PhysRevLett.118.036601.