APS -APS March Meeting 2017 - Event - Magnetic excitations in the one-dimensional cuprate Sr$_{mathrm{mathbf{2}}}$extbf{CuO}$_{mathrm{mathbf{3}}}$extbf{ probed by resonant inelastic x-ray scattering}

摘要

We present a resonant inelastic x-ray scattering (RIXS) study of low energy spectra at the oxygen K-edge of Sr$_{mathrm{2}}$CuO$_{mathrm{3}}$. The experimental data shows the presence of several low-energy excitations in the quasi-elastic region ($omega $extless 0.5 eV), which we associate with magnetic and lattice excitations. We investigate the system using a one dimensional antiferromagnetic Heisenberg chain comprising of copper and oxygen. Using linear spin wave theory, we compute the RIXS cross section in the ultrashort core-hole lifetime approximation to second order and demonstrate the presence of two-magnon excitations in the low-energy region. Phonon and phonon assisted two-magnon excitations are also calculated within our approach. Our analysis establishes that the two-magnon excitations and phonon excitations are present in Sr$_{mathrm{2}}$CuO$_{mathrm{3}}$, indicating that this is potentially an ideal system for studying possible spin-lattice coupling.