Publication

Back to overview

Correlation of the superconducting critical temperature with spin and orbital excitations in (CaxLa1-x)(Ba1.75-xLa0.25+x)Cu3Oy as measured by resonant inelastic x-ray scattering

Type of publication Peer-reviewed
Publikationsform Original article (peer-reviewed)
Publication date 2015
Author Ellis David Shai, Huang Yao-Bo, Olalde-Velasco Paul, Dantz Marcus, Pelliciari Jonathan, Drachuck Gil, Ofer Rinat, Bazalitsky Galina, Berger Jorge, Schmitt Thorsten, Keren Amit,
Project Mott Physics Beyond the Heisenberg Model in Iridates and Related Materials
Show all

Original article (peer-reviewed)

Journal PHYSICAL REVIEW B
Volume (Issue) 92(10)
Page(s) 104507
Title of proceedings PHYSICAL REVIEW B
DOI 10.1103/PhysRevB.92.104507

Open Access

URL http://infoscience.epfl.ch/record/226816
Type of Open Access Repository (Green Open Access)

Abstract

Electronic spin and orbital (dd) excitation spectra of (CaxLa1−x )(Ba1.75−xLa0.25+x)Cu3Oy samples are measured by resonant inelastic x-ray scattering (RIXS). In this compound, Tc of samples with identical hole dopings is strongly affected by the Ca/Ba substitution x due to subtle variations in the lattice constants, while crystal symmetry and disorder as measured by linewidths are x independent. We examine two extreme values of x and two extreme values of hole-doping content y corresponding to antiferromagnetic and superconducting states. The x dependence of the spin-mode energies is approximately the same for both the antiferromagnetic and superconducting samples. This clearly demonstrates that RIXS is sensitive to the superexchange J even in doped samples. A positive correlation between J and the maximum of Tc at optimal doping (T max c) is observed. We also measured the x dependence of the dxy→dx2−y2 and dxz/yz→dx2−y2 orbital splittings. We infer that the effect of the unresolved d3z2−r2→dx2→y2 excitation on T max c is much smaller than the effect of J. There appears to be dispersion in the dxy→dx2−y2 peak of up to 0.05 eV. Our fitting furthermore indicates an asymmetric dispersion for the dxz/yz→dx2−y2 excitation. A peak at ∼0.8 eV is also observed and attributed to a dd excitation in the chain layer.
-