1. University of Vienna Faculty of Physics Vienna Center for Quantum Science and Technology (VCQ) Vienna 1090 Austria
2. AIT Austrian Institute of Technology Center for Digital Safety & Security Vienna Austria
3. Department of Physics and Astronomy University of Exeter Exeter EX4 4QL UK
4. ICFO‐Institut de Ciencies Fotoniques The Barcelona Institute of Science and Technology Castelldefels Barcelona 08860 Spain
5. ICREA‐Institució Catalana de Recerca i Estudis Avançats Passeig Lluís Companys 23 Barcelona 08010 Spain
6. Christian Doppler Laboratory for Photonic Quantum Computer, Faculty of Physics University of Vienna Boltzmanngasse Vienna 1090 Austria
7. Research Platform for Testing the Quantum and Gravity Interface (TURIS) University of Vienna Vienna 1090 Austria