Single-Flux-Quantum Based Coincidence Circuits Using Nb/AlO<i><sub>x</sub></i>/Nb Josephson Junctions with Critical Current Density of 10 kA/cm<sup>2</sup>
We demonstrated a coincidence circuit based on single flux quantum (SFQ) circuits with high-time accuracy for a two-photon interferometer using superconducting nanostrip photon detectors (SNSPDs). The coincidence circuit was designed to have 3 different time windows of 30 ps, 100 ps, and 200 ps, which can be selectable on demand. Furthermore, each time window can be fine-tuned by changing the applied bias currents. The circuit was fabricated by the AIST high-speed standard process based on Nb/AlOx/Nb junctions with critical current density of 10 kA/cm2. We experimentally evaluated the time window of the coincidence circuit at temperatures below 2.4 K in a 0.1-W Gifford-McMahon (GM) cryocooler.
Authors
- Hirotaka Terai (ORCID: https://orcid.org/0000-0002-5575-2221)
- Shigeyuki Miyajima (ORCID: https://orcid.org/0000-0002-5153-5537)
- Shigehito Miki (ORCID: https://orcid.org/0000-0001-5575-6532)
Institutions
- National Institute of Information and Communications Technology (JP)
Publication Details
- Journal
- IEICE Transactions on Electronics
- Published
- 2024-11-27
- DOI
- https://doi.org/10.1587/transele.2024sei0002
- Primary Topic
- Physics of Superconductivity and Magnetism
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Institute of Advanced Industrial Science and Technology
- Ministry of Education, Culture, Sports, Science and Technology