Impurity states and the absence of quasiparticle localization in disordered {ital d}-wave superconductors

Journal Article · Fri Mar 01 04:00:00 EST 1996 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.76.2386· OSTI ID:284460

Balatsky, A V; Salkola, M I ^[1]

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1. Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

The absence of localization of impurity-induced low-energy quasiparticle states in a 2D {ital d}-wave superconductor is shown for any amount of disorder in the limit of unitary scatterers. This result follows from the fact that a unitary impurity produces a marginally bound state at zero energy which decays as a power law along the nodes of the {ital d}-wave energy gap. Consequently, for finite density of impurities, the impurity-induced states are coupled by long-range overlaps yielding extended quasiparticle states below a characteristic energy scale {omega}{sub {ital c}}. Simple scaling arguments suggest that {omega}{sub {ital c}}{proportional_to}{ital e}{sup {minus}{ital c}/{ital n}{sub imp}}, with {ital n}{sub imp} the impurity density and {ital c} a positive constant. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 284460
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 13 Vol. 76; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ENERGY GAP
IMPURITIES
ORDER PARAMETERS
QUASI PARTICLES
SCALING LAWS
SUPERCONDUCTORS
SYMMETRY