Current induced hidden states in Josephson junctions
Josephson junctions enable dissipation-less electrical current through metals and insulators below a critical current. Despite being central to quantum technology based on superconducting quantum bits and fundamental research into self-conjugate quasiparticles, the spatial distribution of super current flow at the junction and its predicted evolution with current bias and external magnetic field remain experimentally elusive. Revealing the hidden current flow, featureless in electrical resistance, helps understanding unconventional phenomena such as the nonreciprocal critical current, i.e., Josephson diode effect. Here we introduce a platform to visualize super current flow at the nanoscale. Utilizing a scanning magnetometer based on nitrogen vacancy centers in diamond, we uncover competing ground states electrically switchable within the zero-resistance regime. The competition results from the superconducting phase re-configuration induced by the Josephson current and kinetic inductance of thin-film superconductors. We further identify a new mechanism for the Josephson diode effect involving the Josephson current-induced phase. The nanoscale super current flow emerges as a new experimental observable for elucidating unconventional superconductivity, and optimizing quantum computation and energy-efficient devices.
Authors
- Uri Vool (ORCID: https://orcid.org/0000-0001-6024-8241)
- Patrick Maletinsky (ORCID: https://orcid.org/0000-0003-1699-388X)
- Shaowen Chen (ORCID: https://orcid.org/0000-0001-7254-1023)
- David A. Broadway (ORCID: https://orcid.org/0000-0002-7375-8766)
- Seunghyun Park (ORCID: https://orcid.org/0009-0003-2851-9250)
- Amir Yacoby (ORCID: https://orcid.org/0000-0002-5737-7963)
- Nikola Maksimovic (ORCID: https://orcid.org/0000-0002-4540-6579)
- Ady Stern (ORCID: https://orcid.org/0000-0002-9493-268X)
- Bertrand I. Halperin (ORCID: https://orcid.org/0000-0002-6999-1039)
- Tony Zhou (ORCID: https://orcid.org/0000-0002-8451-3385)
- Mykhailo Flaks (ORCID: https://orcid.org/0000-0003-2731-2752)
Institutions
- Harvard University (US)
- University of Basel (CH)
- Harvard University Press (US)
- Northrop Grumman (United States) (US)
- Max Planck Institute for Chemical Physics of Solids (DE)
- Northrop Grumman (Germany) (DE)
- Weizmann Institute of Science (IL)
Publication Details
- Journal
- Nature Communications
- Published
- 2024-09-14
- DOI
- https://doi.org/10.1038/s41467-024-52271-z
- Citations
- 19
- Primary Topic
- Quantum and electron transport phenomena
- Type
- article
- Field-Weighted Citation Impact
- 6.41
Funders
- National Science Foundation
- U.S. Department of Energy
- Gordon and Betty Moore Foundation
- European Commission
- Deutsche Forschungsgemeinschaft
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- Israel Science Foundation
- Horizon 2020 Framework Programme
- Division of Materials Research
- Army Research Office