dc SQUID near the quantum noise limit

Conference · Thu Jan 01 00:00:00 EST 1981

OSTI ID:6454048

Van Harlingen, D J; Koch, R H; Clarke, J

A series of dc SQUIDs has been fabricated in an attempt to obtain quantum-limited sensitivity. Typically, the SQUID inductance, L, is 2 pH, the capacitance and critical current of each tunnel junction are 0.5 pF and 0.5 mA, and the shunt resistance for each junction is 1..cap omega... The measured spectral density of the voltage noise S/sub v/ contains a l/f component that extends typically to 100 kHz or higher. When the l/f component is subtracted out, the best energy sensitivity achieved to date is epsilon/1Hz = S/sub v//2L(delta V/delta PHI)/sup 2/ less than or approximately equal to 2h, where delta V/delta PHI is the transfer coefficient.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6454048
• Report Number(s): LBL-12450; CONF-810809-10
• Resource Relation: Conference: 16. international conference on low temperature physics, Los Angeles, CA, USA, 19 Aug 1981
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
SQUID DEVICES
DC SYSTEMS
PERFORMANCE
BACKGROUND NOISE
EXPERIMENTAL DATA
LIMITING VALUES
SENSITIVITY
DATA
ELECTRONIC EQUIPMENT
ENERGY SYSTEMS
EQUIPMENT
FLUXMETERS
INFORMATION
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
NOISE
NUMERICAL DATA
POWER SYSTEMS
SUPERCONDUCTING DEVICES
420201* - Engineering- Cryogenic Equipment & Devices