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Manifestation of spin-charge separation in the dynamic dielectric response of one--dimensional Sr2CuO3

R. Neudert·M. Knupfer·M. S. Golden·J. Fink·W. Stephan·K. Penc·N. Motoyama·H. Eisaki·S. Uchida
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Abstract

We have determined the dynamical dielectric response of a one-dimensional, correlated insulator by carrying out electron energy-loss spectroscopy on Sr2CuO3 single crystals. The observed momentum and energy dependence of the low-energy features, which correspond to collective transitions across the gap, are well described by an extended one-band Hubbard model with moderate nearest neighbor Coulomb interaction strength. An exciton-like peak appears with increasing momentum transfer. These observations provide experimental evidence for spin-charge separation in the relevant excitations of this compound, as theoretically expected for the one-dimensional Hubbard model.

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R. Neudert, M. Knupfer, M. S. Golden, J. Fink, W. Stephan, K. Penc, N. Motoyama, H. Eisaki, S. Uchida. 1998-06-22. Manifestation of spin-charge separation in the dynamic dielectric response of one--dimensional Sr2CuO3. https://doi.org/10.1103/physrevlett.81.657

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