Quantum limited quasiparticle mixers at 100 GHz

Conference · Sat Sep 01 04:00:00 EDT 1990

OSTI ID:5904611

Mears, C A; Hu, Qing; Richards, P L ^[1]; Worsham, A H; Prober, D E ^[2]; Raeisaenen, A V ^[3]

---

1. Lawrence Berkeley Lab., CA (USA)
2. Yale Univ., New Haven, CT (USA). Dept. of Applied Physics
3. Helsinki Univ. of Technology, Espoo (Finland). Radio Lab.

We have made accurate measurements of the noise and gain of superconducting-insulating-superconducting (SIS) mixers employing small area (1{mu}m{sup 2}) Ta/Ta{sub 2}O{sub 5}/Pb{sub 0.9}Bi{sub 0.1} tunnel junctions. We have measured an added mixer noise of 0.61 +/{minus} 0.31 quanta at 95.0 GHz, which is within 25 percent of the quantum limit of 0.5 quanta. We have carried out a detailed comparison between theoretical predictions of the quantum theory of mixing and experimentally measured noise and gain. We used the shapes of I-V curves pumped at the upper and lower sideband frequencies to deduce values of the embedding admittances at these frequencies. Using these admittances, the mixer noise and gain predicted by quantum theory are in excellent agreement with experiment. 21 refs., 9 figs.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• Sponsoring Organization: DOE; NSF; USDOE, Washington, DC (USA); National Science Foundation, Washington, DC (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5904611
• Report Number(s): LBL-28991; CONF-900944--43; ON: DE91011894; CNN: ECS-8604350; AFOSR-88-0270
• Country of Publication: United States
• Language: English

Related Subjects

426001 -- Engineering-- Superconducting Devices & Circuits-- (1990-)
656100* -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC EQUIPMENT
EQUIPMENT
FREQUENCY MIXING
HETERODYNE RECEIVERS
JUNCTIONS
MEASURING METHODS
MICROWAVE EQUIPMENT
PERFORMANCE
PHYSICAL PROPERTIES
RADIO EQUIPMENT
REFRACTORY METAL COMPOUNDS
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTIVITY
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS