Fermi-liquid damping and NMR relaxation in superconductors

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.5696· OSTI ID:282069

Tewari, S; Ruvalds, J ^[1]

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1. Department of Physics, University of Virginia, Charlottesville, Virginia 22903 (United States)

Electron collisions for a two-dimensional Fermi-liquid (FL) are shown to give a quasiparticle damping with interesting frequency and temperature variations in the BCS superconducting state. The spin susceptibility which determines the structure of the damping is analyzed in the normal state for a Hubbard model with a constant on-site Coulomb repulsion. This is then generalized to the superconducting state by including coherence factors and self-energy and vertex corrections. Calculations of the NMR relaxation rate reveal that the FL damping structure can reduce the Hebel-Slichter peak, in agreement with data on the organic superconductor (MDT-TTF){sub 2}AuI{sub 2} (methylenedithiotetrathiafulvalene salt). However, the strongly suppressed FL damping in the superconducting state does not eliminate the Hebel-Slichter peak, and thus suggests that other mechanisms are needed to explain the NMR data on (TMTSF){sub 2}ClO{sub 4} (bistetramethyltetraselenafulvaleneperchlorate), the BEDT organic compounds, and cuprate superconductors. Predictions of the temperature variation of the damping and the spin response are given over a wide frequency range as a guide to experimental probes of the symmetry of the superconducting pairs. {copyright} {ital 1996 The American Physical Society.}

• DOE Contract Number: FG05-84ER45113
• OSTI ID: 282069
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 9 Vol. 53; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BCS THEORY
CHLORATES
COULOMB FIELD
CUPRATES
D WAVES
ELECTRON-ELECTRON COUPLING
ELECTRON-PHONON COUPLING
ENERGY GAP
FERMI GAS
HIGH-TC SUPERCONDUCTORS
HUBBARD MODEL
NUCLEAR MAGNETIC RESONANCE
ORDER PARAMETERS
ORGANIC SUPERCONDUCTORS
SELF-ENERGY
SPIN-SPIN RELAXATION
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
TMTSF