Measurement-induced generation of spatial entanglement in a two-dimensional quantum walk with single-qubit coin

TL;DR

This paper explores a measurement-based approach to generate spatial entanglement in two-dimensional quantum walks, offering a potentially less complex alternative to standard methods and comparing it with the Grover walk.

Contribution

It introduces a measurement-induced scheme for spatial entanglement generation in 2D quantum walks, extending previous models and comparing results with the Grover walk.

Findings

Measurement on the coin enhances spatial entanglement.

The scheme reduces experimental complexity compared to standard walks.

Comparison shows advantages over the Grover walk in certain scenarios.

Abstract

One of the proposals for the exploitation of two-dimensional quantum walks has been the efficient generation of entanglement. Unfortunately, the technological effort required for the experimental realization of standard two-dimensional quantum walks is significantly demanding. In this respect, an alternative scheme with less challenging conditions has been recently studied, particularly in terms of spatial-entanglement generation [C. Di Franco, M. Mc Gettrick, and Th. Busch, Phys. Rev. Lett. 106, 080502 (2011)]. Here, we extend the investigation to a scenario where a measurement is performed on the coin degree of freedom after the evolution, allowing a further comparison with the standard two-dimensional Grover walk.