Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 0801.0101

Local quasiparticle lifetimes in a d-wave superconductor

S. Graser·P. J. Hirschfeld·D. J. Scalapino
View original source ↗Read source document ↗Export metadata ↓

Abstract

Scanning tunnelling spectroscopy (STS) measurements find that the surface of Bi-2212 is characterized by nanoscale sized regions, "gap patches," which have different magnitudes for the d-wave energy gap. Recent studies have shown that the tunnelling conductance can be fit using a BCS-type density of states for a d-wave superconductor with a local quasiparticle scattering rate. The fit is made with a scattering rate which varies linearly with energy and has a slope that is positively correlated with the local value of the gap. We revisit a model of quasiparticle scattering by impurities and spin fluctuations which was previously used to describe the lifetimes of nodal quasiparticles measured by angle-resolved photoemission (ARPES). We argue that the broadening of the local density of states is in general determined by the imaginary part of the self-energy of the system averaged over a small region. The size of this region is set by a mean free path which depends upon the energy. At low energies, this region is found to be significantly larger than a gap "patch", so that the density of states measured by STS is homogeneous in this energy range. At higher energies where the mean free path is comparable with the patch size, the density of states is inhomogeneous. We show that a local self-energy in the impurity-plus-spin fluctuation model, while not strictly linear, yields a local density of states (LDOS) nearly identical to the full theory, and argue that it is consistent with the STS data as well as the phenomenological linear scattering rate extracted from experiment. We also explore the qualitative consequences of this phenomenology for the spectral widths observed in ARPES and predict the existence of Fermi arcs in the superconducting state.

Explore related subjects

cond-mat.supr-con

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S. Graser, P. J. Hirschfeld, D. J. Scalapino. 2007-12-30. Local quasiparticle lifetimes in a d-wave superconductor. https://doi.org/10.1103/physrevb.77.184504

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Short-Range Modulated Electron Lattice and d-Wave Superconductivity in Cuprates: A Phenomenological Ginzburg-Landau Framework

A short-range charge modulation near 0.3 reciprocal lattice units along the Cu-O bond is present in every hole-doped cuprate family. Resonant x-ray scattering now shows that superconductivity does two opposite things to it at once: below Tc the modulation weakens yet becomes more phase coherent. We trace this split to symmetry: the modulation's envelope carries lattice momentum, which leaves a d-wave condensate exactly two ways to couple to it at quartic order, through the modulation's amplitude or through its phase. The first moves amplitude, coherence, and superfluid stiffness together; the second buys coherence at the expense of stiffness, so the two are separately measurable. We call this Ginzburg-Landau framework the modulated electron lattice (MEL). Classical Monte Carlo on 120x120 lattices with quenched disorder places the x-ray observation, read as a single component, at competing amplitude coupling and cooperative phase coupling, where the model gives no stiffness gain. But the measured intensity sums bond-centred and site-centred components. A two-component simulation gives the same pair of bulk signatures, intensity down and coherence up, both with a stiffness loss and with a stiffness gain, depending on the strength of the bond channel. Bulk data therefore cannot say whether this charge order stiffens the superconductor or softens it. What settles the question is the bond-channel amplitude, which form-factor-resolved scattering and phase-resolved tunnelling measure. The response follows the local pairing amplitude, so its onset need not be sharp at Tc. We also compute vortex pinning in the modulated landscape and obtain an in-plane penetration depth of about 124 nm once the transition temperature fixes the energy scale. This version corrects the first: its linear envelope coupling was symmetry-forbidden, and all numerical results are new.

cond-mat.supr-con↗
arXiv2026

Collective excitation-mediated transport in nanoscale Josephson junctions that exhibit quantum confinement

Quantum confinement can strongly modify transport through Josephson junctions. Here, we study local tunneling transport through nanoscale Josephson junction stacks in the Coulomb blockade regime, where the metallic layers exhibit strong vertical quantum confinement. We find that quasiparticle transport is strongly enhanced by a collective excitation mode intrinsic to the junction and localized in the isolated metallic overlayer. We quantify both the collective-mode energy and the Coulomb gap and show that both exhibit strong layer-dependent modulation, consistent with the modulation of the underlying quantum well states. We further investigate how the collective excitation responds to various perturbations, including mechanical motion and an applied magnetic field. Our results suggest that this collective mode is sensitive to quasiparticles near the Fermi level and may therefore provide an indirect probe of the superconducting state.

cond-mat.supr-con↗
arXiv2026

Universal Dzyaloshinski-Moriya interaction dictates pairing in unconventional superconductor families

The collinear-antiferromagnetic spin-fluctuation paradigm has long guided unconventional superconductivity research, yet fails to reconcile the noncollinear spin phenomena observed across cuprates, iron-based superconductors, and nickelates. Using extensive first-principles calculations and unbiased large-scale DMRG simulations, we show that Dzyaloshinski-Moriya interaction (DMI)-arising from local inversion-symmetry breaking-is a common ingredient across these families. This DMI unifies hallmark observations in parent compounds-incommensurate orders, spin-wave gaps, and noncollinear textures. Under hole doping, strong DMI drives spin vortices to merge with pi-shifted hole stripes, forming hybrid vortex-hole stripe phases. These phases stabilize charge order while supporting, not suppressing, superconductivity. By contrast, under electron doping, these vortices pin holes and suppress long-range superconductivity. Our results establish DMI as a unifying link between noncollinear magnetism and superconductivity, identifying hole-strip-vortex coupling as a microscopic pairing engine. Given that DMI is common across major superconductor families, these findings challenge the prevailing pairing mechanism and offer an experimentally testable roadmap for materials optimization.

cond-mat.supr-con↗