Orbital Occupancy Order inV2O3: Resonant X-Ray Scattering Results

Resonant x-ray scattering experiments at the vanadium $K$ edge demonstrate the existence of orbital ordering in ${\mathrm{V}}_2{\mathrm{O}}_3$. Bragg peaks due to the long-range order of $3d$ orbitals occupancy are observed when the photon energy is tuned to the threshold of the vanadium $3d$ bands. The azimuthal dependence of the resonant intensities confirms that the resonance arises from the ordering of the vanadium orbital occupancy. The observed orbital structure accounts for the complex magnetic structure of ${\mathrm{V}}_2{\mathrm{O}}_3$. The measured magnetic and orbital responses have the same critical temperature $T_N$.