Entangling two defects via a surrounding crystal

TL;DR

This paper theoretically demonstrates how two impurity defects in a crystal can become entangled through their interaction with the surrounding lattice, with potential realizations in various quantum systems.

Contribution

It introduces a method for entangling two defects via a crystalline environment, showing independence from chain size and slow decay with distance, applicable to multiple physical platforms.

Findings

Entanglement occurs in sufficiently cold chains and specific initial states.

Entanglement is independent of the chain size.

Entanglement decays slowly with impurity separation.

Abstract

We theoretically show how two impurity defects in a crystalline structure can be entangled through coupling with the crystal. We demonstrate this with a harmonic chain of trapped ions in which two ions of a different species are embedded. Entanglement is found for sufficiently cold chains and for a certain class of initial, separable states of the defects. It results from the interplay between localized modes which involve the defects and the interposed ions, it is independent of the chain size, and decays slowly with the distance between the impurities. These dynamics can be observed in systems exhibiting spatial order, viable realizations are optical lattices, optomechanical systems, or cavity arrays in circuit QED.