Engineering steady entanglement for trapped ions at finite temperature by dissipation

TL;DR

This paper introduces a dissipative technique to reliably generate maximally entangled steady states of two trapped ions at finite temperature, leveraging engineered dissipation and controlled spontaneous emission.

Contribution

It presents a novel method combining unitary operations and dissipation to produce entanglement independent of initial states and temperature effects.

Findings

Deterministic Bell state preparation achieved regardless of initial conditions.

The method allows violation of CHSH inequality at finite temperature.

Effective coupling is independent of phonon-number fluctuations.

Abstract

We propose a dissipative method for preparation of a maximally entangled steady state of two trapped ions in the Lamb-Dicke limit. By addressing the trapped-ion system with a monochromatic standing wave laser pulse of frequency resonant with the ionic transition and a microwave field coupled to the ground-state transitions, we obtain an effective coupling between two particles, which is independent of the phonon-number fluctuations. Meanwhile, the controlled spontaneous emission of trapped ions is implemented via pumping the metastable states upwards to the short-lived ionic states by an auxiliary laser field. Combining the unitary processes with the engineered dissipation, a deterministic Bell state can be produced irrespective of the initial states of systems. Moreover, our result shows that the CHSH inequality can be violated for a wide range of decoherence parameters, even at finite temperature.