  Nonreciprocal photonic devices play a significant role in regulating the
propagation of electromagnetic waves. Here we theoretically investigate the
nonreciprocal properties of transverse magnetic modes in a one-dimensional
graphene-based photonic crystal subjected to an applied electrical DC bias. We
find that drifting electrons driven by the external DC electric field can give
rise to extremely asymmetric dispersion diagrams. Furthermore, when the
drifting electrons travel antiparallel to the normal component of the incident
wave vector, the negative refraction is strongly suppressed, causing the energy
of light to flow along the direction of the direct electric current. Our
theoretical findings can be used to design nonreciprocal nanophotonic devices
and enable light to propagate without refraction.
