Holographic hydrodynamics of tilted Dirac materials

We present a gravity dual to a quantum material with tilted Dirac cone in 2+1 dimensional spacetime. In this many-body system the electronics degrees of freedom are strongly-coupled, constitute a Dirac fluid and admit an effective hydrodynamic description. The holographic techniques are applied to compute the thermodynamic variables and hydrodynamic transports of a fluid on the boundary of an asymptotically anti de Sitter spacetime with a boosted black hole in the bulk. We find that these materials exhibit deviations from the normal Dirac fluid which rely on the tilt of the Dirac cone. In particular, the shear viscosity to entropy density ratio is reduced and the KSS bound is violated in this system. This prediction can be experimentally verified in two-dimensional quantum materials (e.g. organic & alpha;-(BEDT-TTF)(2)I-3 and 8Pmmn borophene) with tilted Dirac cone.

Automated summary

We propose a gravity dual for a quantum material with a tilted Dirac cone in 2+1 dimensions. The electrons in this many-body system are strongly coupled, forming a Dirac fluid, and can be described hydrodynamically. Holographic techniques are used to compute the thermodynamic variables and hydrodynamic transports of a fluid on the boundary of an asymptotically anti de Sitter spacetime with a boosted black hole in the bulk. We find deviations from the normal Dirac fluid in these materials due to the tilt of the Dirac cone, including a reduced shear viscosity to entropy density ratio and violation of the KSS bound. This prediction can be experimentally tested in two-dimensional quantum materials with tilted Dirac cone, such as organic α-(BEDT-TTF)(2)I-3 and 8Pmmn borophene.