Collective cyclotron motion of the relativistic plasma in graphene
  We present a theory of the finite temperature thermo-electric response functions of graphene, in the hydrodynamic regime induced by electron-electron collisions. In moderate magnetic fields, the Dirac particles undergo a collective cyclotron motion with a temperature-dependent relativistic cyclotron frequency proportional to the net charge density of the Dirac plasma. In contrast to the undamped cyclotron pole in Galilean-invariant systems (Kohn's theorem), here there is a finite damping induced by collisions between the counter-propagating particles and holes. This cyclotron motion shows up as a damped pole in the frequency dependent conductivities, and should be readily detectable in microwave measurements at room temperature. We also discuss the large Nernst effect to be expected in graphene. 
Markus Mueller and Subir Sachdev