  We investigate the phase structure and conductivity of a relativistic fluid
in a circulating electric field with a transverse magnetic field. This system
exhibits behavior similar to other driven systems such as strongly coupled
driven CFTs [Rangamani2015] or a simple anharmonic oscillator. We identify
distinct regions of fluid behavior as a function of driving frequency, and
argue that a "phase" transition will occur. Such a transition could be
measurable in graphene, and may be characterized by sudden discontinuous
increase in the Hall conductivity. The presence of the discontinuity depends on
how the boundary is approached as the frequency or amplitude is dialed. In the
region where two solution exists the measured conductivity will depend on how
the system is prepared.
