Critical dimension of inhomogeneous gap states in nonequilibrium superconductors under large injection of quasiparticles via tunneling

Journal Article · Thu Apr 01 04:00:00 EST 1982 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.25.4467· OSTI ID:6579380

Akoh, H; Kajimura, K

Inhomogeneous energy-gap states in nonequilibrium Pb-In alloy films have been studied under high-energy injection of quasiparticles via tunneling. Two types of configuration of double tunnel junctions (Pb--In-Pb--In-Pb) have been used in the experiment: In the first configuration, T/sub I/, geometrical dimensions of both injectors and detectors of the junctions were changed precisely and quasicontinuously. The second configuration, T/sub II/, consisted of a long in-line injector and very narrow multiple detectors. For samples with T/sub I/ configuration, coexistence of two different energy gaps was observed only in samples with dimensions above a critical sample size of about 25 x 25 ..mu..m/sup 2/, while in samples with dimensions below the critical size a first-order transition from the superconducting state with a broad but reduced energy gap to the normal state was observed. The results indicate that the inhomogeneous energy-gap state possesses a critical characteristic dimension with a macroscopic size in nonequilibrium superconductors. Spatial structures of the inhomogeneous-gap state were measured by using samples with T/sub II/ configuration. The spatial structure was found to be affected dominantly by the macroscopic sample boundary. These inhomogeneous-gap states are discussed by current theories of nonequilibrium instabilities.

• Research Organization: Electrotechnical Laboratory, Sakura-mura, Ibaraki 305, Japan
• OSTI ID: 6579380
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Journal Issue: 7 Vol. 25:7; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
DATA
ELECTRONIC STRUCTURE
ENERGY GAP
EXPERIMENTAL DATA
FILMS
INDIUM ALLOYS
INFORMATION
JUNCTIONS
LEAD ALLOYS
NUMERICAL DATA
QUASI PARTICLES
SUPERCONDUCTING JUNCTIONS
TUNNEL EFFECT