Distributed entangled state production by using quantum repeater protocol

TL;DR

This paper proposes a quantum repeater protocol using optomechanical systems to generate entanglement between distant three-level atoms, avoiding complex Bell measurements and analyzing entropy and success probability.

Contribution

It introduces a novel optomechanical-based quantum repeater protocol for entanglement distribution between distant atoms, with practical measurement strategies.

Findings

Entanglement between distant atoms is achieved without Bell measurements.

Increasing mechanical frequency enhances entropy periods.

Decreasing optomechanical coupling improves success probability.

Abstract

We consider entangled state production utilizing a full optomechanical arrangement, based on which we create entanglement between two far three-level V-type atoms using a quantum repeater protocol. At first, we consider eight identical atoms (1; 2;...; 8), while adjacent pairs (i; i + 1) with i = 1; 3; 5; 7 have been prepared in entangled states and the atoms 1, 8 are the two target atoms. The three-level atoms (1,2,3,4) and (5,6,7,8) distinctly become entangled with the system including optical and mechanical modes by performing the interaction in optomechanical cavities between atoms (2,3) and (6,7), respectively. Then, by operating appropriate measurements, instead of Bell state measurement which is a hard task in practical works, the entangled states of atoms (1,4) and (5,8) are achieved. Next, via interacting atoms (4,5) of the pairs (1,4) and (5,8) and operating proper measurement, the entangled state of target atoms (1,8) is obtained. In the continuation, entropy and success probability of the produced entangled state are then evaluated. It is observed that the time period of entropy is increased by increasing the mechanical frequency and by decreasing optomechanical coupling strength to the field modes. Also, in most cases, the maximum of success probability is increased by decreasing G and via decreasing.