Direct spectroscopic evidence of holons in a quantum antiferromagnetic spin-1/2 chain

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Casa DM, Chuang YD, Li Y, Montano P, Beno M, Hussain Z, Eisaki H, Uchida S, Gog T, Casa DM

Abstract:
We report charge dynamics of a quantum spin-1/2 chain (SrCuO2) over the complete Brillouin zone using the momentum tunability of inelastic X-ray scattering. Excitations at the insulating gap edge are found to be highly dispersive. Observed dispersions are consistent with charge fluctuations involving holons unique to 1-D spin-1/2 quantum systems.