Hong-Ou-Mandel interferometry on a biphoton beat note

Funding

We thank Thomas Scheidl, Sebastian Ecker, Soeren Wengerowsky, Johannes Handsteiner, Siddarth Joshi, and Lukas Bulla for experimental support and helpful conversations. Y. C. thanks Lijun Chen for support. The research leading to these results has received funding from the H2020 European Programme under Grant Agreement 801060 Q-MIC, the Austrian Research Promotion Agency (FFG) Projects-Agentur fur Luft-und Raumfahrt (FFG-ALR contract 6238191 and 866025), the European Space Agency (ESA contract 4000112591/14/NL/US), as well as the Austrian Academy of Sciences. Y.C. acknowledges personal funding from Major Program of National Natural Science Foundation of China (No. 11690030, 11690032), National Key Research and Development Program of China (2017YFA0303700); the National Natural Science Foundation of China (No. 61771236), and from a Scholarship from the China Scholarship Council (CSC) and the program B for Outstanding PhD candidate of Nanjing University. This work was supported by the Fraunhofer Internal Programs under Grant No. Attract 066-604178. J.P.T. acknowledges financial support from Fundacio Cellex, from the Government of Spain through the Severo Ochoa Programme for Centres of Excellence in R&D (SEV-2015-0522), from Generalitat de Catalunya under the programs ICREA Academia and CERCA, and from the project 17FUN01 BeCOMe within the Programme EMPIR, and initiative co-founded by the European Union and the EMPIR Participating Countries.