Media type: E-Article; Text Title: Spectral Hong–Ou–Mandel Interference between Independently Generated Single Photons for Scalable Frequency-Domain Quantum Processing Contributor: Khodadad Kashi, Anahita [Author]; Kues, Michael [Author] imprint: Weinheim : Wiley VCH, 2021 Published in: Laser and Photonics Reviews 15 (2021), Nr. 5 ; Laser and Photonics Reviews Issue: published Version Language: English DOI: https://doi.org/10.15488/12275; https://doi.org/10.1002/lpor.202000464 ISSN: 1863-8880 Keywords: Degrees of freedom (mechanics) ; photonic frequency-domain processing ; Frequency circuits ; Bosons ; bi-chromatic two-photon state ; Processing applications ; Two-photon interference ; Electrooptic phase modulator ; Telecom infrastructures ; independently generated single photons ; Frequency domain analysis ; Degree of freedom ; Different frequency ; Scalability ; Photons ; Mixer circuits ; Hong–Ou–Mandel interference ; Frequency-domain processing Origination: Footnote: Diese Datenquelle enthält auch Bestandsnachweise, die nicht zu einem Volltext führen. Description: The photon's frequency degree of freedom, being compatible with mature telecom infrastructure, offers large potential for the stable and controllable realization of photonic quantum processing applications such as the quantum internet. The Hong–Ou–Mandel effect, as a two-photon interference phenomenon, serves as a central building block for such frameworks. A key element yet missing to enable meaningful frequency-based implementations as well as scalability in the number of processed photons, is the demonstration of the Hong–Ou–Mandel effect between independently created photons of different frequencies. The experimental implementation of bosonic and fermionic frequency domain Hong–Ou–Mandel interference between independently generated single photons is reported here, with measured visibilities of 74.31% ± 3.56% and 86.44% ± 8.27%, respectively. This is achieved through a scalable photonic frequency circuit that creates two post-selected pure single photons, which undergo frequency mixing at an electro-optic phase modulator. The system is on-the-fly reconfigurable allowing to probe bosonic and fermionic Hong–Ou–Mandel interference in the same experimental setup. The work demonstrates the versatility of frequency domain processing and its scalability toward higher photon numbers, which enables new quantum gate concepts as well as the establishment of frequency-based large-scale quantum networks. © 2021 The Authors. Laser & Photonics Reviews published by Wiley-VCH GmbH Access State: Open Access Rights information: Attribution - Non Commercial - No Derivs (CC BY-NC-ND)