High {Tc} superconductor tunnel junctions for photon detectors
- Illinois Inst. of Tech., Chicago, IL (United States)
- Argonne National Lab., IL (United States)
SIN and SIS quasiparticle tunnel junctions on high T{sub c} superconductors (HTS) offer the possibility of low-noise, heterodyne, photon detection in the THz regime. We report progress on the development of such junctions using mechanical point contacts. In general, these contacts display the optimum characteristics that can be obtained from HTS native-surface tunnel barriers. The bismuthate, Ba{sub 1-x}K{sub x}BiO{sub 3}, (T{sub c}=25K) displays ideal, BCS, quasiparticle characteristics at T=4.2 K however, at temperatures T{approximately}T{sub c}/2 there is evidence of strong quasiparticle damping which may.inhibit device performance. The cuprates typically display non-ideal quasiparticle characteristics including large sub-gap conductances. Recent data for the new Hg-based cuprates (T{sub c}96K) are promising in that they exhibit very low and flat sub-gap conductances as expected from a BCS density of states. Proximity effect tunnel junctions on Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}/Au bilayers have been studied using an In tip. An induced energy gap has been consistently observed in the Au layer and the data can be understood using the McMillan model. A few junctions show much improved sub-gap characteristics compared to ones made directly on the BSCCO surface and indicate that this approach may be suitable for mixer development
- Research Organization:
- Argonne National Lab., IL (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 10130388
- Report Number(s):
- ANL/MSD/CP-82165; CONF-940132-2; ON: DE94007686; CNN: Contract DMR 91-20000
- Resource Relation:
- Conference: International conference on millimeter and submillimeter waves,San Diego, CA (United States),10-14 Jan 1994; Other Information: PBD: Feb 1994
- Country of Publication:
- United States
- Language:
- English
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