A truncated photon
Quantum Physics
2026-05-27 v2
Abstract
An elementary particle such as a photon cannot be cut in two pieces. Still it must be possible to truncate a photon with an optical shutter. The result is neither another photon nor a mix of a photon and a vacuum. Instead it is a superposition and mix of photon numbers up to infinity. This state is rather complicated, but nevertheless locally equivalent to a single photon or vacuum to the left and right, respectively, of a narrow transition region.
Cite
@article{arxiv.2510.21636,
title = {A truncated photon},
author = {Isak Cecil Onsager Rukan and Jan Gulla and Johannes Skaar},
journal= {arXiv preprint arXiv:2510.21636},
year = {2026}
}
Comments
13 pages, 2 figures. Accepted for publication in Physical Review Letters