Graphene - a nearly perfect fluid

Understand

Hydrodynamics and collision dominated transport are crucial to understand the slow dynamics of many correlated quantum liquids.

• The ratio \eta/s of the shear viscosity \eta to the entropy density s is uniquely suited to determine how strongly the excitations in a quantum fluid interact.
• We determine \eta/s in clean undoped graphene using a quantum kinetic theory.
• As a result of the quantum criticality of this system the ratio is smaller than in many other correlated quantum liquids and, interestingly, comes close to a lower bound conjectured in the context of the quark gluon plasma.