Disorder-assisted distribution of entanglement in XY spin chains

作者：Almeida Guilherme M A^*; de Moura Francisco A B F; Apollaro Tony J G; Lyra Marcelo L

来源：Physical Review A, 2017, 96(3): 032315.

DOI：10.1103/PhysRevA.96.032315

We study the creation and distribution of entanglement in disordered XY-type spin-1/2 chains for the paradigmatic case of a single flipped spin prepared on a fully polarized background. The local magnetic field is set to follow a disordered long-range-correlated sequence with power-law spectrum. Depending on the degree of correlations of the disorder, a set of extended modes emerges in the middle of the band yielding an interplay between localization and delocalization. As a consequence, a rich variety of entanglement distribution patterns arises, which we evaluate here through the concurrence between two spins. We show that, even in the presence of disorder, the entanglement wave can be pushed to spread out, reaching distant sites, and also to enhance pairwise entanglement between the initial site and the rest of the chain. We also study the propagation of an initial maximally entangled state through the chain and show that correlated disorder improves the transmission quite significantly when compared with the uncorrelated counterpart. Our work contributes in designing solid-state devices for quantum information processing in the realistic setting of correlated static disorder.

• 出版日期2017-9-11