Creation and localization of entanglement in a simple configuration of coupled harmonic oscillators

TL;DR

This paper explores how nonclassical states in a simple coupled harmonic oscillator system can create and localize entanglement, with potential applications in solid-state quantum computing.

Contribution

It demonstrates that nonclassical states can localize entanglement in coupled oscillators, preventing distant entanglement, and proposes a possible electromechanical implementation.

Findings

Nonclassical states can generate entanglement in coupled oscillators.

Entanglement can be localized, preventing it from spreading to distant oscillators.

Potential application in solid-state quantum computing systems.

Abstract

We investigate a simple arrangement of coupled harmonic oscillators which brings out some interesting effects concerning creation of entanglement. It is well known that if each member in a linear chain of coupled harmonic oscillators is prepared in a ``classical state'', such as a pure coherent state or a mixed thermal state, no entanglement is created in the rotating wave approximation. On the other hand, if one of the oscillators is prepared in a nonclassical state (pure squeezed state, for instance), entanglement may be created between members of the chain. In the setup considered here, we found that a great family of nonclassical (squeezed) states can localize entanglement in such a way that distant oscillators never become entangled. We present a detailed study of this particular localization phenomenon. Our results may find application in future solid state implementations of quantum computers, and we suggest an electromechanical system consisting of an array of coupled micromechanical oscillators as a possible implementation.