Abstract
We develop an analytical tool to extract bulk electronic properties of unconventional superconductors from inelastic neutron scattering spectra. We show that the upward and downward branches of the spin excitation spectra have distinct origins, with the upper branch representing a gapped spin-wave dispersion and the lower branch associated with Bogoliubov quasiparticle scattering on the Fermi surface. Combined, they produce an "hourglass" dispersion with 45 degrees rotation of the spectrum, as found experimentally. The downward dispersion can be inverted to reveal the Fermi momentum dispersion of the single-particle spectrum as well as the corresponding superconducting (SC) gap function, analogously to the quasiparticle interference effect in scanning tunneling microscopy (STM). Whereas angle-resolved photoemission spectroscopy and STM provide surface-sensitive information, this inversion procedure provides bulk electronic properties. The technique is essentially model independent and can be applied to a wide variety of materials.
Keywords
Bogoliubox quasiparticle scattering, scanning tunneling microscopy, STM, superconducting gap properties
Subject Categories
Fermi surfaces, Scattering (Physics), Neutrons
Disciplines
Physics
Publisher
American Physical Society
Publication Date
2-9-2012
Rights Information
Copyright 2012 American Physical Society.
Rights Holder
American Physical Society
Recommended Citation
Das, Tanmoy; Markiewicz, R. S.; and Bansil, A., "Reconstructing the bulk Fermi surface and superconducting gap properties from neutron scattering experiments" (2012). Physics Faculty Publications. Paper 421.
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Notes
Originally published in Physical Review B v.85 (2012): 064510. DOI: 10.1103/PhysRevB.85.064510