Selective focusing of electrons and holes in a graphene-based   superconducting lens
  We show that a graphene pnp junction with a central superconducting electrode acts as a Veselago lens for incoming electrons by focusing them and their phase-conjugated counterpart (holes) into different points of the optical axis. This selective focusing suggested by a simple trajectory analysis is confirmed by fully microscopic calculations. Although the focusing pattern is degraded by deviations from the ideal conditions we show that it remains visible for a wide range of parameters. We discuss how this property can be useful for the detection of entangled electron pairs. 
S. Gomez, P. Burset, W. J. Herrera and A. Levy Yeyati
cond-mat.mes-hall cond-mat.supr-con