Impurities and conductivity in a D-wave superconductor

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:68447

Balatsky, A V ^[1]

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1. Los Alamos National Laboratory, NM (United States)

It is well known that scalar impurities are pair breakers in d-wave and any other nontrivial pairing state superconductor. They produce a finite lifetime of the quasiparticles in the nodes of the gap, a finite density of states at low energy, and a finite low frequency conductivity at low temperatures, ignoring localization effects. For the special case of a 2D superconductor with a d-wave gap, a straight-forward calculation yields the suprising result that dc conductivity {sigma}({omega} {yields} 0) is a {open_quotes}universal{close_quotes} number, independent of the lifetime of quasiparticle (but dependent on the aniosotropy ratio of the velocities of the quasiparticle in the node of the gap). However, recent experiments on microwave absorption in YBCO crystals with Zn impurities show a linear temperature dependence of the conductivity for pure samples, evolving to the quadratic behavior for higher impurity concentration, and low-temperature conductivity, inversely proportional to the impurity concentration.

• Research Organization: Los Alamos National Lab., NM (United States)
• OSTI ID: 68447
• Report Number(s): LA-UR--94-1148; CONF-931247--; ON: DE94009293
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BARIUM OXIDES
COPPER OXIDES
ELECTRIC CONDUCTIVITY
HIGH-TC SUPERCONDUCTORS
IMPURITIES
TEMPERATURE DEPENDENCE
YTTRIUM OXIDES
ZINC