Impact of Electrical Contacts Design and Materials on the Stability of Ti Superconducting Transition Shape
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Cardiff Univ., Cardiff (United Kingdom)
- Stanford Univ., Stanford, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, Chicago, IL (United States)
- National Inst. of Standards and Technology (NIST), Boulder, CO (United States)
- Univ. of California, Berkeley, CA (United States)
- Univ. of Chicago, Chicago, IL (United States)
- Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of Chicago, Chicago, IL (United States)
- McGill Univ., Montreal, QC (Canada)
- McGill Univ., Montreal, QC (Canada); Canadian Institute for Advanced Research, Toronto (Canada)
- Univ. of Colorado, Boulder, CO (United States)
- Case Western Reserve Univ., Cleveland, OH (United States)
- Univ. of Illinois, Urbana, IL (United States); Argonne National Lab. (ANL), Argonne, IL (United States)
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Univ. of Illinois, Urbana, IL (United States)
- Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Univ. of Toronto, Toronto, ON (Canada)
- Three-Speed Logic, Inc.Vancouver (Canada)
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)
- Stanford Univ., Stanford, CA (United States)
- Univ. of California, Los Angeles, CA (United States); Univ. of California, Berkeley, CA (United States)
The South Pole Telescope SPT-3G camera utilizes Ti/Au transition edge sensors (TESs). A key requirement for these sensors is reproducibility and long-term stability of the superconducting (SC) transitions. Here, we discuss the impact of electrical contacts design and materials on the shape of the SC transitions. Using scanning electron microscope, atomic force microscope, and optical differential interference contrast microscopy, we observed the presence of unexpected defects of morphological nature on the titanium surface and their evolution in time in proximity to Nb contacts. We found direct correlation between the variations of the morphology and the SC transition shape. Experiments with different diffusion barriers between TES and Nb leads were performed to clarify the origin of this problem. In conclusion, we have demonstrated that the reproducibility of superconducting transitions can be significantly improved by preventing diffusion processes in the TES-leads contact areas.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States); SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- National Science Foundation (NSF); Gordon and Betty Moore Foundation; USDOE Office of Science (SC), High Energy Physics (HEP); USDOE
- Contributing Organization:
- SPT
- Grant/Contract Number:
- AC02-06CH11357; AC02-76SF00515; PLR-1248097; PHY-1125897; AST-0956135; GBMF 947; AC02-07CH11359
- OSTI ID:
- 1491023
- Alternate ID(s):
- OSTI ID: 1490471; OSTI ID: 1497093
- Report Number(s):
- FERMILAB-PUB-18-741-AE-PPD; 140107
- Journal Information:
- Journal of Low Temperature Physics, Vol. 193, Issue 5-6; ISSN 0022-2291
- Publisher:
- Plenum PressCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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