2015/02/13 by Matteo D 'Astuto, 'Astuto, Matteo D, Sylvain Denis +23
Physics and Astronomy · #FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1502.04003
arxiv created 2015/02/13 · arxiv updated 2015/02/16
We find excitations lower in energy than known phonon modes in underdoped La_2-xSr_xCuO_4+δ (x=0.08), with both inelastic X-Ray scattering (IXS) and inelastic neutron scattering (INS). A non dispersive excitation at 9 meV is identified and is also seen by INS in (La,Nd)_2-xSr_xCuO_4+δ, with 40% Nd substitution. INS also identifies a still lower energy dispersive mode at low q in the Nd free sample. These modes are clearly distinct from the longitudinal acoustic phonon and correspond in energy to the Zone Centre modes measured by optical spectroscopy and associated with stripe dynamics.