Linear optics-based entanglement concentration protocols for cluster-type entangled coherent state

Abstract

We proposed two linear optics based entanglement concentration protocols (ECPs) to obtain maximally entangled 4-mode Cluster-type entangled coherent state (ECS) from less (partially) entangled Cluster-type ECS. The first ECP is designed using a superposition of single-mode coherent state with two unknown parameters, whereas the second ECP is obtained using a superposition of single-mode coherent state and a superposition of two-mode coherent state with four unknown parameters. The success probabilities have been calculated for both the ECPs. Necessary quantum circuits enabling future experimental realizations of the proposed ECPs are provided using linear optical elements. Further, the benefit of the proposed schemes is established in the context of long distance quantum communication where photon loss is an obstruction.

Entanglement Concentration Protocols for GHZ-type Entangled Coherent State Based on Linear Optics

“…Further, among the generation of various ECSs (in theory and experiment) like W-type ECS [39], Cluster-type ECS [37,38,40], the generation schemes of GHZ-type ECS have also been put forward in theory and experiment [37,39]. Moreover, many applications in quantum communication [40,41] using Cluster-type ECS, quantum cryptography using two-mode squeezed states [42], quantum teleportation using 3-mode ECS [43,44] and quantum key distribution using GHZ-type ECS [45], quantum computation [46,47] using Cluster-type ECS and quantum information processing tasks [48] using W-type ECS [49] have been proposed so far, that have reflected the significance of ECSs [37][38][39][40] and motivated the recently reported CV-based ECPs [50][51][52] (and references therein), too. In particular, Sheng et al proposed ECP for Bell-type ECS [50] and W-type ECS [51].…”

“…In particular, Sheng et al proposed ECP for Bell-type ECS [50] and W-type ECS [51]. Subsequently, Mitali et al [52] designed two ECPs for Cluster-type ECS based on linear optics. Independently, the hybrid ECPs have also attracted the recent interest of the researchers [53,54].…”