| Autor: |
Sunil Ghimire, Kamal R Joshi, Amlan Datta, Aidan Goerdt, Makariy A Tanatar, Deborah Schlagel, Matthew J Kramer, Jayss Marshall, Cameron J Kopas, Joshua Y Mutus, Alexander Romanenko, Anna Grassellino, Ruslan Prozorov |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
|
| Zdroj: |
Materials for Quantum Technology, Vol 4, Iss 4, p 045201 (2024) |
| Druh dokumentu: |
article |
| ISSN: |
2633-4356 |
| DOI: |
10.1088/2633-4356/ad8c0c |
| Popis: |
The London penetration depth, $\lambda(T)$ , was measured in various forms of niobium, including foils, thin films, single crystals, and samples from superconducting radio-frequency (SRF) cavities. We observed a significant difference in $\lambda(T)$ at low temperatures, $T \lt T_\mathrm{c}/3$ , due to low-energy quasiparticles. In particular, an unusual downturn of $\lambda(T)$ on cooling in the SRF cavity samples required to take into account deep in-gap bound states. Theoretical modeling using the generalized Dynes density of states shows that such in-gap states lead to a downturn or a peak in $\lambda(T)$ upon cooling. Combined, experimental and theoretical findings provide a method for detecting two-level systems or states related to magnetic impurities in the bulk of niobium. This result is particularly relevant for the quantum informatics sciences technologies used in qubits and circuit quantum electrodynamics architecture based on SRF cavities. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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