Effects of non-local initial conditions in the quantum walk on the line

Abstract

We report an enhancement of the decay rate of the survival probability when non-local initial conditions in position space are considered in the quantum walk on the line. It is shown how this interference effect can be understood analytically by using previously derived results. Within a restricted position subspace, the enhanced decay coexists with a maximum asymptotic entanglement level while the normal decay rate corresponds to initial relative phases associated to a minimum asymptotic entanglement level.