Quantum correlations of identical particles subject to classical environmental noise

TL;DR

This paper introduces a measure for quantum discord of indistinguishable particles and studies how classical environmental noise affects quantum correlations in a two-particle quantum walk system, revealing protective effects of on-site interactions.

Contribution

It proposes a new measure for quantum discord of indistinguishable particles and analyzes its behavior under classical noise in a quantum walk system.

Findings

Quantum discord correlates with entanglement of particles.

On-site interactions protect quantum correlations against decoherence.

Classical noise impacts quantum correlations similarly to entanglement.

Abstract

In this work we propose a measure for the quantum discord of indistinguishable particles, based on the definition of entanglement of particles given in [H. M. Wiseman et al., Phis. Rev. Lett 91, 097902 (2003)]. This discord of particles is then used to evaluate the quantum correlations in a system of two identical bosons (fermions), where the particles perform a quantum random walk described by the Hubbard hamiltonian in a 1D lattice. The dynamics of the particles is either unperturbed or subject to a classical environmental noise - such as random telegraph, pink or brown noise. The observed results are consistent with those for the entanglement of particles, and we observe that on-site interaction between particles have an important protective effect on correlations against the decoherence of the system.