# Swapping path-spin intraparticle entanglement onto spin-spin interparticle entanglement

## TL;DR

This paper proposes a novel protocol to transfer intraparticle path-spin entanglement of a single particle into interparticle spin-spin entanglement between two separate particles, using a Mach-Zehnder setup and unitary operations.

## Contribution

It introduces a new method for entanglement swapping that utilizes intraparticle hybrid entanglement as a resource for interparticle entanglement.

## Key findings

- Successfully transfers intraparticle entanglement to interparticle entanglement.
- Enables use of intraparticle entanglement as a resource.
- Provides a protocol for entanglement swapping with spatially separated particles.

## Abstract

Based on a scheme that produces an entanglement between the spin and the path variables of a single spin-1/2 particle (qubit) using a beam-splitter and a spin-flipper, we formulate a procedure for transferring this intraparticle hybrid entanglement to an interparticle entanglement between the spin variables of two other spatially separated spin-1/2 particles which never interact with each other during the entire process. This procedure of entanglement swapping is accomplished by a Mach-Zehnder setup in conjunction with the Stern-Gerlach measuring device, using suitable unitary operations. The proposed protocol, thus, enables the use of intraparticle entanglement as a resource - a feature that has remained unexplored.