Surface States in Holographic Weyl Semimetals
  We study the surface states of a strongly coupled Weyl semimetal within holography. By explicit numerical computation of an inhomogeneous holographic Weyl semimetal we observe the appearance of an electric current restricted to the surface in presence of electric chemical potential. The total current is universal in the sense that it only depends on the topology of the phases showing that the bulk-boundary correspondence holds even at strong coupling. The implications of this result are subtle and may shed some light on anomalous transport at weak coupling. 
Martin Ammon, Markus Heinrich, Amadeo Jim\'enez-Alba, Sebastian   Moeckel
hep-th cond-mat.str-el