Manifestations of symmetry and internal phases in unconventional superconductors

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:6982303

Bark, H

A study of unconventional superconductivity is presented. The general Ginzburg-Landau approach based on the broken symmetry is reviewed. By introducing the coupling between the antiferromagnetic and superconducting ordering which belongs to the [sup 1]E[sub g] representation of the D[sub 4h] group, we obtain nine possible phase diagrams of the heavy fermion superconductor URu[sub 2]Si[sub 2] in the H-T plane. The domain wall formed by two time reversed states of the mixture order parameter belonging to A[sub 1g] [+-] iB[sub 1g] representation of the tetragonal group results in a weak superconducting region which acts as a carrier against the current flow by having a lower critical density than bulk. The orientation dependence of the Josephson current is studied. The current passing through dependence the bicrystalline grain boundaries is investigated as a function of misalignment angle. The current decreases as the misalignment angle increases in general. Symmetry-restricted form of transport coefficient tensors is tabulated for multi-dimensional order parameters of the tetragonal and hexagonal systems. A brief discussion of superconducting fluctuations is given in the appendix.

• Research Organization: Wisconsin Univ., Madison, WI (United States)
• OSTI ID: 6982303
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360207* -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
665411 -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTINIDE ALLOYS
ALLOYS
DIAGRAMS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
GINZBURG-LANDAU THEORY
PHASE DIAGRAMS
PHYSICAL PROPERTIES
PLATINUM METAL ALLOYS
RUTHENIUM ALLOYS
SILICON ALLOYS
SUPERCONDUCTIVITY
SYMMETRY BREAKING
URANIUM ALLOYS