Simple dc-SQUID system based on a frequency modulated relaxation oscillator

Conference · Wed Mar 01 04:00:00 EST 1989 · IEEE Trans. Magn.; (United States)

OSTI ID:6091705

Muck, M; Heiden, C

Nanobridges with hysteretic I-V-characteristics can be operated as relaxation oscillators when connected to an R-L shunt. A dc-SQUID configuration results, if two such oscillators are incorporated in a superconducting ring. Operating such a self-oscillating SQUID or SOS With a suitable bias current leads to an output signal of the order of 10 mV, whose frequency depends on the magnetic flux through the SQUID-ring modulo PHI/sub o/. Due to this large output voltage, no impedance matching nor a special low noise preamplifier are needed for the read-out scheme. Standard integrated circuits for fm signal processing can be used leading to matchbox-size electronics. Such dc-SQUIDS have been made of thin Nb, NbN, and Nb/sub 3/Ge films, the highest sensitivity resulting so far for Nb devices with a white flux noise below 10%-5% PHI/sub o//..sqrt.. Hz at 4.2 K.

• Research Organization: Institut fur Schicht- und Ionentechnik, Kernforschungsanlage Julich, 5170 Julich (DE)
• OSTI ID: 6091705
• Report Number(s): CONF-880812-
• Conference Information: Journal Name: IEEE Trans. Magn.; (United States) Journal Volume: 25:2
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204 -- Ceramics
Cermets
& Refractories-- Physical Properties
42 ENGINEERING
420201* -- Engineering-- Cryogenic Equipment & Devices
420800 -- Engineering-- Electronic Circuits & Devices-- (-1989)
656100 -- Condensed Matter Physics-- Superconductivity
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AMPLIFIERS
DESIGN
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC CIRCUITS
ELECTRONIC EQUIPMENT
EQUIPMENT
FILMS
FLUXMETERS
FREQUENCY MODULATION
HYSTERESIS
INTEGRATED CIRCUITS
MAGNETIC FLUX
MEASURING INSTRUMENTS
MICROELECTRONIC CIRCUITS
MICROELECTRONICS
MICROWAVE EQUIPMENT
MODULATION
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITRIDES
NITROGEN COMPOUNDS
NOISE
OSCILLATORS
PHYSICAL PROPERTIES
PNICTIDES
REFRACTORY METAL COMPOUNDS
SIZE
SQUID DEVICES
SUPERCONDUCTING DEVICES
SUPERCONDUCTIVITY
THIN FILMS
TRANSITION ELEMENT COMPOUNDS