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Title: Two- and three-dimensional incommensurate modulation in optimally-doped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}

Abstract

X-ray scattering measurements on optimally doped single crystal samples of the high-temperature superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} reveal the presence of three distinct incommensurate charge modulations, each involving a roughly fivefold increase in the unit cell dimension along the b direction. The strongest scattering comes from the well known (H, K{+-}0.21, L) modulation and its harmonics. However, we also observe broad diffraction which peak up at the L values complementary to those which characterize the known modulated structure. These diffraction features correspond to correlation lengths of roughly a unit cell dimension, {xi}{sub c}{approx}20 A in the c direction, and of {xi}{sub b}{approx}185 A parallel to the incommensurate wave vector. We interpret these features as arising from three-dimensional incommensurate domains and the interfaces between them, respectively. In addition we investigate the recently discovered incommensurate modulations which peak up at (1/2, K{+-}0.21, L) and related wave vectors. Here we explicitly study the L dependence of this scattering and see that these charge modulations are two dimensional in nature with weak correlations on the scale of a bilayer thickness, and that they correspond to short-range, isotropic correlation lengths within the basal plane. We relate these new incommensurate modulations to the electronic nanostructuremore » observed in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} using STM topography.« less

Authors:
;  [1];  [1];  [2];  [3];  [4];  [5];  [6]
  1. Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada L8S 4M1 (Canada)
  2. (Canada)
  3. Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland)
  4. Department of Physics, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)
  5. Department of Physics, University of California, San Diego, California 92093 (United States)
  6. Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
Publication Date:
OSTI Identifier:
20788164
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics; Journal Volume: 73; Journal Issue: 17; Other Information: DOI: 10.1103/PhysRevB.73.174505; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BISMUTH COMPOUNDS; CALCIUM COMPOUNDS; CORRELATIONS; CUPRATES; DOPED MATERIALS; HARMONICS; HIGH-TC SUPERCONDUCTORS; INTERFACES; MODULATION; MONOCRYSTALS; NANOSTRUCTURES; SCANNING TUNNELING MICROSCOPY; STRONTIUM COMPOUNDS; THREE-DIMENSIONAL CALCULATIONS; X-RAY DIFFRACTION

Citation Formats

Castellan, J. P., Dabkowska, H. A., Gaulin, B. D., Canadian Institute for Advanced Research, 180 Dundas St. W., Toronto, Ontario, Canada M5G 1Z8, Nabialek, A., Gu, G., Liu, X., and Islam, Z. Two- and three-dimensional incommensurate modulation in optimally-doped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. United States: N. p., 2006. Web. doi:10.1103/PHYSREVB.73.1.
Castellan, J. P., Dabkowska, H. A., Gaulin, B. D., Canadian Institute for Advanced Research, 180 Dundas St. W., Toronto, Ontario, Canada M5G 1Z8, Nabialek, A., Gu, G., Liu, X., & Islam, Z. Two- and three-dimensional incommensurate modulation in optimally-doped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}. United States. doi:10.1103/PHYSREVB.73.1.
Castellan, J. P., Dabkowska, H. A., Gaulin, B. D., Canadian Institute for Advanced Research, 180 Dundas St. W., Toronto, Ontario, Canada M5G 1Z8, Nabialek, A., Gu, G., Liu, X., and Islam, Z. Mon . "Two- and three-dimensional incommensurate modulation in optimally-doped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}". United States. doi:10.1103/PHYSREVB.73.1.
@article{osti_20788164,
title = {Two- and three-dimensional incommensurate modulation in optimally-doped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}},
author = {Castellan, J. P. and Dabkowska, H. A. and Gaulin, B. D. and Canadian Institute for Advanced Research, 180 Dundas St. W., Toronto, Ontario, Canada M5G 1Z8 and Nabialek, A. and Gu, G. and Liu, X. and Islam, Z.},
abstractNote = {X-ray scattering measurements on optimally doped single crystal samples of the high-temperature superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} reveal the presence of three distinct incommensurate charge modulations, each involving a roughly fivefold increase in the unit cell dimension along the b direction. The strongest scattering comes from the well known (H, K{+-}0.21, L) modulation and its harmonics. However, we also observe broad diffraction which peak up at the L values complementary to those which characterize the known modulated structure. These diffraction features correspond to correlation lengths of roughly a unit cell dimension, {xi}{sub c}{approx}20 A in the c direction, and of {xi}{sub b}{approx}185 A parallel to the incommensurate wave vector. We interpret these features as arising from three-dimensional incommensurate domains and the interfaces between them, respectively. In addition we investigate the recently discovered incommensurate modulations which peak up at (1/2, K{+-}0.21, L) and related wave vectors. Here we explicitly study the L dependence of this scattering and see that these charge modulations are two dimensional in nature with weak correlations on the scale of a bilayer thickness, and that they correspond to short-range, isotropic correlation lengths within the basal plane. We relate these new incommensurate modulations to the electronic nanostructure observed in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} using STM topography.},
doi = {10.1103/PHYSREVB.73.1},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 17,
volume = 73,
place = {United States},
year = {Mon May 01 00:00:00 EDT 2006},
month = {Mon May 01 00:00:00 EDT 2006}
}
  • Tunneling spectroscopy measurements are reported on single crystals of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} using vacuum tunneling and point-contact methods. A reproducible dip feature in the tunneling conductance is found near {vert_bar}eV{vert_bar}=2{Delta}, observed for {ital both} voltage polarities in the best resolved spectra. With overdoping the position of the dip continues to scale with {Delta}, and its magnitude decreases as {Delta} decreases. These results indicate that the dip feature arises from a strong-coupling effect whereby the quasiparticle lifetime is decreased at a characteristic energy of {approximately}2{Delta}, consistent with an electron-electron pairing interaction. {copyright} {ital 1997} {ital The American Physical Society}
  • We present Raman spectra of low and high-energy charge and spin excitations in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8-{delta}} single crystals with an optimized critical temperature of 95 K. The prominent feature of the high-energy background at around 250 meV is a rearrangement of spectral weight in B{sub 1g} and A{sub 1g}+B{sub 2g} symmetry below the critical temperature, similar to the observations in underdoped and optimally doped Y-123 compounds. In the low-energy region, which is influenced by the effects at higher energies, a gap feature in B{sub 1g} symmetry is observed yielding a value for the magnitude of the superconducting ordermore » parameter of A=34 meV. This gap feature is influenced by the orthorhombicity of the crystals and except for a small loss of spectral weight below 25 meV, no gap feature is visible in A{sub 1g} scattering geometry.« less
  • For optimally doped Bi{sub 2}Sr {sub 2}CaCu{sub 2}O{sub 8+{delta}} , scattering rates in the normal state are found to have a linear temperature dependence over most of the Fermi surface. In the immediate vicinity of the ({pi}, 0) point, the scattering rates are nearly constant in the normal state, consistent with models in which scattering at this point determines the c -axis transport. In the superconducting state, the scattering rates away from the nodal direction appear to level off and become temperature independent. (c) 2000 The American Physical Society.
  • We report a neutron scattering study of the spin excitation spectrum in the superconducting state of the slightly overdoped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} system (T{sub c}=87 K). We focus on the dispersion of the resonance peak in the superconducting state that is due to a S=1 collective mode. The measured spin excitation spectrum bears a strong similarity to the spectrum of the YBa{sub 2}Cu{sub 3}O{sub 6+x} system for a similar doping level (i.e., x{approx}0.95-1), which can be described as intersecting upward- and downward-dispersing branches. A close comparison of the threshold of the electron-hole spin flip continuum, known from anglemore » resolved photoemission measurements in the same system, indicates that the magnetic response in the superconducting state is confined, in both energy and momentum, below the gapped Stoner continuum. In contrast to YBa{sub 2}Cu{sub 3}O{sub 6+x}, the spin excitation spectrum is broader than the experimental resolution. In the framework of an itinerant-electron model, we quantitatively relate this intrinsic energy width to the superconducting gap distribution observed in scanning tunneling microscopy experiments. Our study further suggests a significant in-plane anisotropy of the magnetic response.« less
  • The compound Bi{sub 10}Sr{sub 15}Fe{sub 10}O{sub 46} is shown to be isostructural with the 80-K superconductor Bi{sub 2}Sr{sub 2}Ca{sub 2}O{sub 8.21}. The incommensurate modulation of the Cu compound is commensurate in the crystal of the Fe compound that was selected. The modulation is caused by the insertion of extra oxygen atoms in the Bi layers and results in corrugated slabs. The structure of the Bi-O layers can be described as roughly 70% of rocksalt type and 30% of oxygen-deficient perovskite type. The results explain the excess oxygen in the superconductor, the mechanism causing the corrugation, and the inelastic bending propertymore » displayed by single crystals. They also reconcile apparently discrepant results about the oxygen distribution in the bismuth layers.« less