We combine high-resolution resonant inelastic x-ray scattering with cluster calculations utilizing a recently derived effective magnetic scattering operator to analyze the polarization, excitation energy, and momentum dependent excitation spectrum of the low-dimensional quantum magnet TiOCl in the range expected for orbital and magnetic excitations (0 - 2.5 eV). Ti 3d orbital excitations yield complete information on the temperature-dependent crystal-field splitting. In the spin-Peierls phase we observe a dispersive two-spinon excitation and estimate the inter- and intra-dimer magnetic exchange coupling from a comparison to cluster calculations.
@article{arxiv.1107.5800,
title = {Two-Spinon and Orbital Excitations of the Spin-Peierls System TiOCl},
author = {Sebastian Glawion and Jakoba Heidler and Maurits W. Haverkort and Laurent C. Duda and Thorsten Schmitt and Vladimir N. Strocov and Claude Monney and Kejin Zhou and Andreas Ruff and Michael Sing and Ralph Claessen},
journal= {arXiv preprint arXiv:1107.5800},
year = {2011}
}