Observation of a 500meV Collective Mode in La${}_{2-x}$Sr${}_x$CuO${}_4$ and Nd${}_2$CuO${}_4$

J. P. Hill, G. Blumberg, Young-June Kim +9

Utilizing resonant inelastic x-ray scattering, we report a previously unobserved mode in the excitation spectrum of La${}_{2-x}$Sr${}_x$CuO${}_4$ at 500 meV. The mode is peaked around th…