Magnetic nature of the 500 meV peak inLa2−xSrxCuO4observed with resonant inelastic x-ray scattering at t

Abstract

We present a comprehensive study of the temperature and doping dependence of the 500 meV peak observed at q = ͑ ,0͒ in resonant inelastic x-ray scattering ͑RIXS͒ experiments on La 2 CuO 4 . The intensity of this peak persists above the Néel temperature ͑T N = 320 K͒, but decreases gradually with increasing temperature, reaching zero at around T = 500 K. The peak energy decreases with temperature in close quantitative accord with the behavior of the two-magnon B 1g Raman peak in La 2 CuO 4 and, with suitable rescaling, agrees with the Raman peak shifts in EuBa 2 Cu 3 O 6 and K 2 NiF 4 . The overall dispersion of this excitation in the Brillouin zone is found to be in agreement with theoretical calculations for a two-magnon excitation. Upon doping, the peak intensity decreases analogous to the Raman mode intensity and appears to track the doping dependence of the spincorrelation length. Taken together, these observations strongly suggest that the 500 meV mode is magnetic in character and is likely a two-magnon excitation.

Bimagnon studies in cuprates with resonant inelastic x-ray scattering at the OKedge. I. Assessment on La2CuO4and comparison with the excita

“…15 shows that these paramagnons are compatible with very high T c superconductivity supported by spin fluctuations. As far as higher order spin excitations are concerned a mixture of single magnon and bimagnon has been observed with Cu L 3 RIXS, 16 while it has been demonstrated that RIXS at the Cu K edge gives experimental access to bimagnon 7,17 in agreement with the theoretical work of Refs. 18-21.…”

“…It has been already demonstrated by Ellis et al 17 that the accurate fitting of the bimagnon energy requires the inclusion of the magnon-magnon interaction so that there is no point in doing this exercise in the present case. Instead it is interesting to test at Cu K edge the basic approach we used in the O K case, with the obvious needed changes.…”

“…While the spectroscopy of magnetic excitations at Cu K has been investigated rather extensively in the last few years, 7,17 the comparison between L 3 and K edges in terms of bimagnon spectral function remains an open issue. Indeed we have just shown that Cu L 3 explores the lower ridge of the bimagnon continuum; this type of sampling is done also at the Cu K edge accordingly to Ref.…”

Neutron scattering studies of spin-phonon hybridization and superconducting spin gaps in the high-temperature superconductorLa2−x(Sr,Ba)xCuOWagman1, Carlo2, Gaudet3 et al. 2016Phys. Rev. B13921View full textAdd to dashboardCite

“…The growths followed the protocols already reported for the nonsuperconducting samples [24][25][26] .…”

Electronic structure of doped lanthanum cuprates studied with resonant inelastic x-ray scattering

“…The quasi-elastic background, which is expected to depend on temperature, was subtracted by using a fit to the energy-gain (hω <0) side of the spectrum as the background. 42 That the spectra overlap with the exception of the NIR feature indicates that the background subtraction procedure is correct, and that the only temperature dependent part is the NIR feature. The upturn of the intensity at ∼1.2 eV is consistent with that observed in Ref.…”