Optical observation of fermionic partons in Kitaev spin balls

We demonstrate a Kitaev spin liquid in a polyhedral cluster and propose detecting its fractional excitations-Majorana spinons-by magnetic Raman scattering. While little polarization dependence of the Raman spectra at sufficiently low temperatures is usual with quantum spin liquids, the present observations are primarily of geometric origin. The Raman scattering intensity peaks melt with increasing temperature, to be more precise, with increasing number of background gauge-flux excitations.