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Title: Neutron scattering study of spin ordering and stripe pinning in superconducting La1.93Sr0.07CuO4

The relationships among charge order, spin fluctuations, and superconductivity in underdoped cuprates remain controversial. We use neutron scattering techniques to study these phenomena in La1.93Sr0.07CuO4 a superconductor with a transition temperature of Tc = 20 K. At T<< Tc, we find incommensurate spin fluctuations with a quasielastic energy spectrum and no sign of a gap within the energy range from 0.2 to 15 meV. A weak elastic magnetic component grows below ~ 10 K, consistent with results from local probes. Regarding the atomic lattice, we have discovered unexpectedly strong fluctuations of the CuO6 octahedra about Cu-O bonds, which are associated with inequivalent O sites within the CuO2 planes. Moreover, we observed a weak elastic (3 30) superlattice peak that implies a reduced lattice symmetry. The presence of inequivalent O sites rationalizes various pieces of evidence for charge stripe order in underdoped La2-xSrxCuO4. The coexistence of superconductivity with quasi-static spin-stripe order suggests the presence of intertwined orders; however, the rotation of the stripe orientation away from the Cu-O bonds might be connected with evidence for a finite gap at the nodal points of the superconducting gap function.
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  1. Brookhaven National Lab. (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.
  2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  3. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
Journal ID: ISSN 1098-0121; PRBMDO; R&D Project: PO010; KC0201060
Grant/Contract Number:
SC00112704; AC05-00OR22725
Accepted Manuscript
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 92; Journal Issue: 17; Journal ID: ISSN 1098-0121
American Physical Society (APS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source (SNS)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States