Nonlinearity-Induced Enhancement of Entanglement in Quantum Walk

Abstract

The quantum entanglement between the coin state and the position in nonlinear quantum walks is investigated. This study reveals that the nonlinearity of the quantum walk has a significant impact on the enhancement of quantum entanglement in an initially separable bipartite system. It is demonstrated that by selecting appropriate nonlinear parameters the initial separable states may turn to be entangled, and even approach to maximal entangled states.