Quantum effects and the resistive transition in superconducting granular films

Journal Article · Mon Aug 01 04:00:00 EDT 1988 · J. Low Temp. Phys.; (United States)

DOI:https://doi.org/10.1007/BF00682102· OSTI ID:5893348

Zwerger, W

Static and dynamic properties of an array of Josephson junctions shunted by Ohmic resistors are discussed within a quantum Ginzburg-Landau theory. The phase diagram at zero temperature is calculated in mean field approximation. It shows that global superconductivity at T = 0 is possible only if the normal-state film resistance R/sub n/ is smaller than a critical value R/sub n//sup c/ which depends only logarithmically on the Josephson coupling and charging energies. The particular value R/sub n//sup c/ = 6.5 k..cap omega.. found in recent experiments on granular films is in reasonable agreement with estimates for these parameters. A phenomenological order parameter relaxation mechanism is introduced and the associated fluctuation-induced conductivity and diamagnetic susceptibility above T/sub c/ are determined. The resulting precursor conductivity does not explain the observed exponential decrease with R/sub n/-R/sub n//sup c/ of the residual resistance at low temperature. However, a very simple model for the resistance due to vortex flow, generalizing the classical Kosterlitz-Thouless picture, is in good agreement with the experimental data.

• Research Organization: Technische Universitaet Muenchen, Garching (Germany, F.R.)
• OSTI ID: 5893348
• Journal Information: J. Low Temp. Phys.; (United States), Journal Name: J. Low Temp. Phys.; (United States) Vol. 72:3-4; ISSN JLTPA
• Country of Publication: United States
• Language: English

Related Subjects

420201 -- Engineering-- Cryogenic Equipment & Devices
656100* -- Condensed Matter Physics-- Superconductivity
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
DIAGRAMS
DIFFUSION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FILMS
GINZBURG-LANDAU THEORY
GRANULAR MATERIALS
JOSEPHSON JUNCTIONS
JUNCTIONS
MAGNETIC FLUX
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
MATERIALS
MEAN-FIELD THEORY
MECHANICS
ORDER PARAMETERS
PHASE DIAGRAMS
PHYSICAL PROPERTIES
QUANTUM MECHANICS
SPIN WAVES
SUPERCONDUCTING FILMS
SUPERCONDUCTING JUNCTIONS
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE