High-dimensional encodings based on temporal modes (TMs) of photonic quantum states provide the foundations for a highly versatile and efficient quantum information science (QIS) framework. Here, we demonstrate a crucial building block for any QIS applications based on TMs: a programmable source of maximally entangled high-dimensional TM states. Our source is based on a parametric down-conversion process driven by a spectrally shaped pump pulse, which facilitates the generation of maximally entangled TM states with a well-defined dimensionality that can be chosen programmatically. We characterize the effective dimensionality of the generated states via measurements of second-order correlation functions and joint spectral intensities, demonstrating the generation of bi-photon TM states with a controlled dimensionality in up to 20 dimensions.
@article{arxiv.2406.04909,
title = {Orchestrating time and color: a programmable source of high-dimensional entanglement},
author = {Laura Serino and Werner Ridder and Abhinandan Bhattacharjee and Jano Gil-Lopez and Benjamin Brecht and Christine Silberhorn},
journal= {arXiv preprint arXiv:2406.04909},
year = {2024}
}