"Magnetic excitations and phonons simultaneously studied by resonant inelastic x-ray scattering in optimally doped Bi1.5 Pb0.55 Sr1.6 La0.4 CuO6+δ "

Y. Y. Peng: M. Hashimoto, M. Moretti Sala, A. Amorese, N. B. Brookes, G. Dellea, W.-S. Lee, M. Minola, T. Schmitt, Y. Yoshida, K.-J. Zhou, H. Eisaki, T. P. Devereaux, Z.-X. Shen, L. Braicovich, and G. Ghiringhelli; Physical Review B, 08/24/15.

Additional Authors: M. Hashimoto, M. Moretti Sala, A. Amorese, N. B. Brookes, G. Dellea, W.-S. Lee, M. Minola, T. Schmitt, Y. Yoshida, K.-J. Zhou, H. Eisaki, T. P. Devereaux, Z.-X. Shen, L. Braicovich, and G. Ghiringhelli

Abstract:

Magnetic excitations in the optimally doped high-Tc superconductor Bi1.5 Pb0.55 Sr1.6 La0.4 CuO6+δ   (OP-Bi2201, Tc ≃34 K) are investigated by Cu L3 edge resonant inelastic x-ray scattering (RIXS), below and above the pseudogap opening temperature. At both temperatures the broad spectral distribution disperses along the (1,0) direction up to ∼350 meV at zone boundary, similar to other hole-doped cuprates. However, above ∼0.22 reciprocal lattice units, we observe a concurrent intensity decrease for magnetic excitations and quasielastic signals with weak temperature dependence. This anomaly seems to indicate a coupling between magnetic, lattice, and charge modes in this compound. We also compare the magnetic excitation spectra near the antinodal zone boundary in the single layer OP-Bi2201 and in the bilayer optimally doped Bi1.5 Pb0.6 Sr1.54 CaCu2 O8+δ   (OP-Bi2212, Tc ≃96 K). The strong similarities in the paramagnon dispersion and in their energy at zone boundary indicate that the strength of the superexchange interaction and the short-range magnetic correlation cannot be directly related to Tc, not even within the same family of cuprates.