Impurity effects on the spin excitation spectrum in anisotropic superconductors

Journal Article · Sat Oct 01 00:00:00 EDT 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.50.10142· OSTI ID:6907807

Hirashima, D S ^[1]

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1. AT T Bell Laboratories, Murray Hill, New Jersey 07974 (United States)

Effects of nonmagnetic and magnetic impurities on [ital d]-wave and extended-[ital s]-wave superconductors in two dimensions are studied. After the effects on the density of states are investigated, the effects on the dynamical spin susceptibility are studied. In the clean limit, the magnetic response has significant wave-vector dependence if the gap has a large anisotropy. When impurities are introduced this dependence is smeared. In the extended-[ital s]-wave superconductor with a fully open gap, the response at low frequencies is strongly suppressed at low temperatures in the clean limit. Magnetic impurities can give rise to low-lying excitations in the gap and enhance the low-frequency magnetic response at low temperatures. It is found, however, that the intensity is still quite weak with a moderate concentration of the impurities. It is discussed how these results can help in the determination of the symmetry of the order parameter of the high-[ital T][sub [ital c]] superconductors.

• OSTI ID: 6907807
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:14; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665411* -- Basic Superconductivity Studies-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANISOTROPY
COLLECTIVE EXCITATIONS
D WAVES
ENERGY-LEVEL DENSITY
ENERGY-LEVEL TRANSITIONS
EXCITATION
IMPURITIES
MAGNETIC PROPERTIES
MAGNETIC SUSCEPTIBILITY
ORDER PARAMETERS
PARTIAL WAVES
PHYSICAL PROPERTIES
S WAVES
SUPERCONDUCTORS
TEMPERATURE DEPENDENCE