Postselected Entangled States by Photon Detection
Quantum Physics
2025-11-19 v1
Abstract
Postselection is a non-deterministic mechanism to entangle subsystems, often used in weakly-excited systems. We here show how highly-excited ensembles of two-level emitters can be entangled by photon detection. A collective spin is formed, characterized by a squeezing parameter detected by far-field measurements. While decoherence is detrimental to this conditional entanglement, successive photon detections act as a purification process and restores the spin squeezing. Our work opens up new avenues for the generation of postselected entanglement in open quantum systems.
Cite
@article{arxiv.2511.14000,
title = {Postselected Entangled States by Photon Detection},
author = {Pedro Rosario and A. Cidrim and R. Bachelard},
journal= {arXiv preprint arXiv:2511.14000},
year = {2025}
}