The reliable distribution of high-dimensional entangled quantum states, an important resource in quantum technologies, through optical fibre networks is challenging due to the need to maintain coherence across multiple modes. Here we demonstrate the distribution of four-dimensional path-encoded entangled quantum states between photonic chips, enabled by a novel multimode phase stabilisation algorithm. The algorithm utilises the reconfigurability of the integrated photonic circuits to complete one iteration of phase stabilisation in just two measurement rounds for an arbitrary number of modes, and requires no additional hardware to the quantum measurements it enables. As a result, we are able to perform complete quantum state tomography across two chips using the minimum number of local projective measurements to verify the fidelity of the distributed entangled state to be 86% (compared to 8.1% without the phase stabilisation) with an entanglement entropy of 0.995+/-0.002.
@article{arxiv.2510.15675,
title = {High-dimensional Path-Encoded Entanglement Distribution Between Photonic Chips Enabled by Multimode Phase Stabilisation},
author = {Molly A. Thomas and Daniel Llewellyn and Patrick W. Yard and Benjamin A. Slater and Caterina Vigliar and Stefano Paesani and Massimo Borghi and Döndü Sahin and John G. Rarity and Leif K. Oxenløwe and Mark G. Thompson and Karsten Rottwitt and Yunhong Ding and Jianwei Wang and Davide Bacco and Jorge Barreto},
journal= {arXiv preprint arXiv:2510.15675},
year = {2025}
}
Comments
6+21 pages, 3+12 figures. (v2: added references to introduction; updated affiliations and corresponding author email)