Josephson pair tunnelling influence on the performance of an SIS mixer near its superconducting gap
We report the investigation of the influence of Josephson pair tunnelling on the sensitivity of an SIS mixer near the superconducting gap of niobium. Hot and cold load measurements were carried out from 600 GHz to 700 GHz, without completely supressing the Josephson effect. We have noticed that when...
| Κύριοι συγγραφείς: | , |
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| Μορφή: | Journal article |
| Έκδοση: |
Terahertz Science and Technology
2011
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| _version_ | 1826303701394915328 |
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| author | Tan, B Yassin, G |
| author_facet | Tan, B Yassin, G |
| author_sort | Tan, B |
| collection | OXFORD |
| description | We report the investigation of the influence of Josephson pair tunnelling on the sensitivity of an SIS mixer near the superconducting gap of niobium. Hot and cold load measurements were carried out from 600 GHz to 700 GHz, without completely supressing the Josephson effect. We have noticed that when measurements were made at bias points near the first Shapiro step, significantly higher values of Y-factor could be obtained with magnetic field strengths that made the Shapiro step sharper, rather then those that supressed the step. This resulted in a significant improvement in noise temperature of the mixer at those bias points. This observation is important for SIS mixers operating at frequencies near or above gap frequency (ωgap) because the warping of the second negative photon step to the positive display side, narrowing down the bias voltage interval in which measurement of the Y-factor at the first photon step could be done. |
| first_indexed | 2024-03-07T06:06:43Z |
| format | Journal article |
| id | oxford-uuid:ee186fe0-4bac-41da-b4db-bc366f2972d2 |
| institution | University of Oxford |
| last_indexed | 2024-03-07T06:06:43Z |
| publishDate | 2011 |
| publisher | Terahertz Science and Technology |
| record_format | dspace |
| spelling | oxford-uuid:ee186fe0-4bac-41da-b4db-bc366f2972d22022-03-27T11:30:07ZJosephson pair tunnelling influence on the performance of an SIS mixer near its superconducting gapJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ee186fe0-4bac-41da-b4db-bc366f2972d2Symplectic Elements at OxfordTerahertz Science and Technology2011Tan, BYassin, GWe report the investigation of the influence of Josephson pair tunnelling on the sensitivity of an SIS mixer near the superconducting gap of niobium. Hot and cold load measurements were carried out from 600 GHz to 700 GHz, without completely supressing the Josephson effect. We have noticed that when measurements were made at bias points near the first Shapiro step, significantly higher values of Y-factor could be obtained with magnetic field strengths that made the Shapiro step sharper, rather then those that supressed the step. This resulted in a significant improvement in noise temperature of the mixer at those bias points. This observation is important for SIS mixers operating at frequencies near or above gap frequency (ωgap) because the warping of the second negative photon step to the positive display side, narrowing down the bias voltage interval in which measurement of the Y-factor at the first photon step could be done. |
| spellingShingle | Tan, B Yassin, G Josephson pair tunnelling influence on the performance of an SIS mixer near its superconducting gap |
| title | Josephson pair tunnelling influence on the performance of an SIS mixer near its superconducting gap |
| title_full | Josephson pair tunnelling influence on the performance of an SIS mixer near its superconducting gap |
| title_fullStr | Josephson pair tunnelling influence on the performance of an SIS mixer near its superconducting gap |
| title_full_unstemmed | Josephson pair tunnelling influence on the performance of an SIS mixer near its superconducting gap |
| title_short | Josephson pair tunnelling influence on the performance of an SIS mixer near its superconducting gap |
| title_sort | josephson pair tunnelling influence on the performance of an sis mixer near its superconducting gap |
| work_keys_str_mv | AT tanb josephsonpairtunnellinginfluenceontheperformanceofansismixernearitssuperconductinggap AT yassing josephsonpairtunnellinginfluenceontheperformanceofansismixernearitssuperconductinggap |