Quantum walk on a square lattice with identical particles

Abstract

We investigate quantum superposition effects in two-dimensional quantum walks of identical particles with different statistics under particle exchange, starting from various different initial configurations. To characterize interparticle correlation dynamics, we focus on joint properties such as two-particle coincidence probabilities and the spread velocity of the interparticle distance. Regarding spatial modes as an environment for the particles internal degrees of freedom, we study the role played by the particle statistics using standard entanglement witnesses, showing that particles possessing fermionic statistics are more resistant to thermalize with their environment. We analyze the presence of multipartite entanglement in the system's degrees of freedom through the Quantum Fisher Information, revealing that fermionic states generated during the walk are better suited to perform quantum metrology tasks. Finally, we discuss the potential for implementing this model using integrated photonic circuits by exploiting $N$-partite entanglement between individual photons.