Cyclotron resonance in bilayer graphene in the hydrodynamic limit

When electron-electron scattering dominates over electron-phonon and impurity scattering, fluid-like flow of charge carriers results, where this dynamic flow is governed by classical fluid mechanics. In a narrow window of temperature and carrier density, the hydrodynamic limit can be achieved in monolayer graphene. Recent work suggests that the hydrodynamic regime is more readily achievable in bilayer graphene as it exhibits no temperature cutoff and providers a wider window in carrier density, which suggests that it is better suited for achieving this hydrodynamic limit than monolayer graphene. In the presence of a magnetic field, a hydrodynamic cryotron resonance arises that departs from the kinematic cyclotron frequency. There is a finite parameter space in temperature and magnetic field in which this departure can be observed, making it possible to explore cyclotron resonance in bilayer graphene using the magneto-optical infrared spectroscopy within and outside the hydrodynamic window. We will present initial measurements of resonant absorption in hydrodynamic bilayer graphene.