Simple scheme for expanding a polarization-entangled W state by adding one photon

TL;DR

This paper presents a straightforward linear optics method to expand polarization-entangled W states by adding a single photon, facilitating scalable quantum entanglement generation.

Contribution

The authors introduce a simple, experimentally feasible scheme for expanding W states using a polarization-dependent beam splitter and post-selection, advancing quantum state engineering.

Findings

Successfully expands W states by adding one photon

Enables generation of larger W states from single photons

Uses only linear optics and post-selection

Abstract

We propose a simple scheme for expanding a polarization-entangled W state. By mixing a single photon and one of the photons in an n-photon W state at a polarization-dependent beam splitter (PDBS), we can obtain an (n+1)-photon W state after post-selection. Our scheme also opens the door for generating n-photon W states using single photons and linear optics.