Coherent Quantum Transport in Photonic Lattices
  Transferring quantum states efficiently between distant nodes of an information processing circuit is of paramount importance for scalable quantum computing. We report on the first observation of a perfect state transfer protocol on a lattice, thereby demonstrating the general concept of trans- porting arbitrary quantum information with high fidelity. Coherent transfer over 19 sites is realized by utilizing judiciously designed optical structures consisting of evanescently coupled waveguide ele- ments. We provide unequivocal evidence that such an approach is applicable in the quantum regime, for both bosons and fermions, as well as in the classical limit. Our results illustrate the potential of the perfect state transfer protocol as a promising route towards integrated quantum computing on a chip. 
Armando Perez-Leija, Robert Keil, Alastair Kay, Hector Moya-Cessa,   Stefan Nolte, Leong-Chuan Kwek, Blas M. Rodr\'iguez-Lar...
quant-ph