Magneto-electric equivalence and emergent electrodynamics in bilayer   graphene
  It is a fundamental paradigm that the physical effects induced by electric fields are qualitatively different from those induced by magnetic fields. Here we show that electrons at a Dirac point in bilayer graphene experience an unusual type of electromagnetism where magnetic and electric fields are virtually equivalent: every coupling of an electron's degrees of freedom to a magnetic field is matched by an analogous coupling of the same degrees of freedom to an electric field. This counter-intuitive duality of matter-field interactions enables novel ways to create and manipulate spin and pseudo-spin polarizations in bilayer graphene via external fields and leads to the emergence of a valley-contrasting axion electrodynamics, where the traditional association of charges at rest with electric fields and charge currents with magnetic fields is reversed. 
R. Winkler (Northern Illinois University), U. Zuelicke (Victoria   University of Wellington)
cond-mat.mes-hall