Entanglement Transfer and C-Not Gate Implemented in A Fiber Connected 3-Atom System

TL;DR

This paper proposes a robust, efficient scheme for transferring unknown entangled states and implementing C-Not gates between two spatially separated atoms via a fiber-connected three-atom system, achieving near-perfect fidelity.

Contribution

It introduces a deterministic method for entanglement transfer and C-Not gate implementation in a fiber-connected three-atom system with high fidelity and insensitivity to common losses.

Findings

High success probability and fidelity for entanglement transfer.

Deterministic C-Not gate implementation with low time cost.

Scheme is insensitive to cavity leakage and fiber loss.

Abstract

A robust scheme for unknown entangled state transfer and C-Not gate implemented between two spatially separated atoms is proposed. It is shown that, in the effective three-atom Ising model, two-atom unknown entangled state can be transferred from one pair of atoms to another deterministically by only repeating a simple operation of turning on/off local laser field applied on atom for two times at controlling time $\frac{\pi}{2\Omega_{0}}$. The whole time cost is less than $\frac{3\pi}{2\Omega_{0}}$. The successful probability and the fidelity are almost 100% for small atomic spontaneous emission rate. Deterministic two-atom C-Not gate can also be implemented in this model by just turning on/off the local laser field applied on the single target atom and leaving the controlling atom in its cavity alone for a while. The whole time cost is less than $\frac{\pi}{2\Omega_{0}}+\frac{3\pi \Delta}{2g^{2}}$. It is demonstrated that the scheme is insensitive to cavity leakage and fiber loss.