Device-quality tunnel junctions on the high {Tc} superconductor HgBa{sub 2}CuO{sub 4+{delta}}

Conference · Sun Jan 01 04:00:00 EST 1995

OSTI ID:10106817

Zasadzinski, J ^[1]; Chen, J; Romano, P; Gray, K E; Wagner, J L; Hinks, D G ^[2]

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1. Illinois Institute of Technology, Chicago, IL (United States)
2. Argonne National Lab., IL (United States)

SIN and SIS tunnel junction devices (e.g. photon detectors, logic elements) require quasiparticle characteristics that exhibit sharp current onsets at the gap voltage and very low sub-gap conductances. Progress is reported on the development of such junctions on High Tc cuprates using mechanical point contacts. In general, these contacts display the optimum characteristics that can be obtained from HTS native-surface tunnel barriers. Most cuprates display a sub-gap conductance which monotonically increases with voltage about the minimum value at zero bias. However, tunneling data of unusually high quality have been obtained for the recently discovered Hg-based cuprate, HgBa{sub 2}CuO{sub 4} (T{sub c}=96K). SIS{prime} tunneling data using a Nb tip are presented which exhibit very low and flat sub-gap conductances and sharp conductance peaks as expected from a BCS density of states. These results are slightly improved over earlier published results with SIN junctions. Use of the experimental data to simulate the performance of a quasiparticle mixer demonstrates that noise temperatures approaching the quantum limit are possible for SIS and SIN mixers in the range 1-5 THz.

• 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: 10106817
• Report Number(s): ANL/MSD/CP--84398; CONF-940926--3; ON: DE95004646; CNN: Contract DMR 91-20000
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360207
BARIUM OXIDES
CALCIUM OXIDES
COPPER OXIDES
FABRICATION
FERMI LEVEL
HIGH-TC SUPERCONDUCTORS
MERCURY OXIDES
QUASI PARTICLES
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTIVITY
TUNNEL EFFECT