Quantum correlations in continuos-time quantum walks of two   indistinguishable particles
  We evaluate the degree of quantum correlation between two fermions (bosons) subject to continuous time quantum walks in a one-dimensional ring lattice with periodic boundary conditions. In our approach, no particle-particle interaction is considered. We show that the interference effects due to exchange symmetry can result into the appearance of non-classical correlations. The role played onto the appearance of quantum correlations by the quantum statistics of the particles, the boundary conditions, and the partition of the system is widely investigated. Quantum correlations also been investigated in a model mimicking the ballistic evolution of two indistinguishable particles in a 1D continuous space structure. Our results are consistent with recent quantum optics and electron quantum optics experiments where the showing up of two-particle non-classical correlations has been observed even in the absence of mutual interaction between the particles. 
Claudia Benedetti, Fabrizio Buscemi, and Paolo Bordone
quant-ph