Noise effects in Josephson junctions

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1983

OSTI ID:6462873

Arai, M R

Effects in Josephson junctions and related circuitry due to noise of varied origin are discussed. First the effects of thermal noise associated with the normal resistance of the junction are evaluated for isolated junctions and phase locked pairs of junctions. The two junction problem is reduced to an effective one junction problem using the method of slowly varying parameters as described by Bogoliubov and Krylov. The statistical problem is then solved using a novel spectral representation which is easily and cheaply implemented on the computer to obtain numerical results. The methods employed are introduced on simple exactly solvable diffusion models for clarification. The technique employed is easily generalized to Brownian motion in arbitrary periodic potentials. Next nonequilibrium noise due to non-ohmic heating of the electronic system is described in detail. The nonequilibrium state arises due to the inability of the phonons to maintain thermal equilibrium in the electronic system at low temperatures. This noise represents a fundamental noise limit for biased resistors at low temperatures and is important in circuits containing Josephson junctions. Finally, practical and theoretical limitations on the precision with which the Josephson effect can measure 2e/h are described. The intrinsic phase fluctuations of the junction are evaluated starting from a functional integral formulation of the tunneling model of the Josephson junction. These intrinsic fluctuations are inversely proportional to the number of electrons in the junction and will be masked by nonequilibrium noise due to heating as well as noise in external voltage standards.

• Research Organization: Cornell Univ., Ithaca, NY (USA)
• OSTI ID: 6462873
• Country of Publication: United States
• Language: English

Related Subjects

656102* -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
FLUCTUATIONS
JOSEPHSON JUNCTIONS
JUNCTIONS
NOISE
NUMERICAL SOLUTION
SUPERCONDUCTING JUNCTIONS
TEMPERATURE DEPENDENCE
TUNNEL EFFECT
VARIATIONS