Quantum fluctuations and dissipation in ultra-thin superconducting films

Thesis/Dissertation · Wed Dec 31 23:00:00 EST 1986

OSTI ID:6159077

Jaeger, H M

The systematic evolution of superconductivity in ultra-thin quench-condensed Ga, Pb, and In films was investigated in detail as their normal-state sheet resistance was decreased by incrementing their nominal thickness. Strikingly similar behavior was found for all three systems. The data indicate a clear distinction between the onset of super-conductivity on first a local and later a global, i.e., sample spanning, level over a total thickness increment of one to two angstroms. The onset of local superconductive coupling appears to occur only below a critical value for the ratio of the measured activation energy in the normal-state to the superconducting gap. The films are modeled a arrays of Josephson junctions with a wide statistical distribution of junction resistances. Analysis of the data indicates the importance of quantum fluctuations due to charging energies. Theoretical models for the coupling of dissipation to these fluctuations are found in agreement with the observed threshold for global super-conductivity.

• Research Organization: Minnesota Univ., Minneapolis (USA)
• OSTI ID: 6159077
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
FILMS
FLUCTUATIONS
GALLIUM
INDIUM
JOSEPHSON JUNCTIONS
JUNCTIONS
LEAD
METALS
PHYSICAL PROPERTIES
SUPERCONDUCTING FILMS
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTIVITY
THICKNESS
VARIATIONS