Encoding quantum information in photonic time-bin states is typically considered impractical for moving free-space quantum communication due to the difficulties with phase stabilization of distant quantum time-bin interferometers and turbulence of free-space channels. We demonstrate a novel approach using reference frame independent time-bin quantum key distribution that completely avoids the need for active relative phase stabilization while simultaneously overcoming a highly multi-mode channel without any active mode filtering. This scheme enables passive, self-compensating time-bin quantum communication without any mode filtering, mode sorting, adaptive optics, active basis selection, or active phase alignment. We realize a proof-of-concept demonstration using hybrid polarization and time-bin entangled photons that demonstrates a sustained asymptotic secure key rate greater than 0.07 bits/coincidence over a 15m multi-mode fiber optical channel and showing entanglement correlations over a moving 38.5dB loss free-space channel, including system losses. The scheme simplifies the use of time-bin encoding and can be readily applied over various spatially multi-mode and fluctuating channels involving rapidly moving platforms, including airborne and satellite systems.
@article{arxiv.2302.05038,
title = {Towards Fully Passive Time-Bin Quantum Key Distribution over Moving Free-Space Channels},
author = {Ramy Tannous and Wilson Wu and Stéphane Vinet and Chithrabhanu Perumangatt and Dogan Sinar and Alexander Ling and Thomas Jennewein},
journal= {arXiv preprint arXiv:2302.05038},
year = {2025}
}
Comments
Published in Vol. 33, No. 17 / 25 Aug 2025 / Optics Express 35635-35648 This document has been formatted in an attempt to match the version of record of the published manuscript. Supplemental material can be found at https://doi.org/10.6084/m9.figshare.29042372