Large charge fluctuation in the one-dimensional Hubbard model

Jie Yang, Jue-lian Shen

Yasushi Shiina

S. Ohmura, A. Takahashi, Kaoru Iwano +5 more

We propose an effective model called the ``charge model,'' for the half-filled one-dimensional Hubbard and extended Hubbard models. In this model, spin-charge separation, which has been justified from an infinite on-site repulsion ($U$) in the strict sense, is compatible with charge fluctuations. Our analyses based on the many-body Wannier functions succeeded in determining the optical conductivity spectra in large systems. The obtained spectra reproduce the spectra for the original models well even in the intermediate $U$ region of $U=5$--$10T$, with $T$ being the nearest-neighbor electron hopping energy. These results indicate that the spin-charge separation works fairly well in this intermediate $U$ region against the usual expectation and that the charge model is an effective model that applies to actual quasi-one-dimensional materials classified as strongly correlated electron systems.

R. Citro, S. Di Matteo, M. Marinaro

R. Citro, S. Di Matteo, M. Marinaro

Norikazu Tomita

Quantum fluctuations in the one dimensional (ID) doped Hubbard model are described by superposition of optimized non-orthogonal Slater determinants. It is explicitly shown that the spin and charge fluctuations are mostly separated as spinons and holons in the strong interaction regime, while the fluctuations due to the spin-charge pled states become important in the weak and intermediate interaction regimes