Showing papers by "Shoji Yamamoto published in 1991"
TL;DR: A macromolecular hemoglobin-binding protein was purified, characterized, and designated as bovine haptoglobin (Hp), and studies using some reducing reagents proved that highly polymerized Hp in serum was composed of 2-20 polymerized forms of alpha 2 beta 2 tetramer.
76 citations
TL;DR: In this article, diradical and zwitterionic breathers are considered, which consist of a neutral and charged soliton-antisoliton pair, respectively, making quantum translational and breathing motions, as local quantum fluctuations in the spin density wave (SDW) order parameter (OP) in the half filled case.
Abstract: The electronic structure of the one dimensional Hubbard model is calculated by the resonating Hartree-Fock (HF) method. Solitons in the spin density wave (SDW) order parameter (OP) make translational bands with a lot of high harmonics. Their effective masses are about 0.1 of the electron mass, so that they are potentially good charge or spin carriers. We consider diradical and zwitterionic breathers, which consist of a neutral and charged soliton-antisoliton pair, respectively, making quantum translational and breathing motions, as local quantum fluctuations in the SDW in the half filled case. The stabilization of the ground state by the resonationg breathers amounts to 76.5% ( U =3) and 70.1% ( U =4) of the correlation energy. This is better than the result of the Gutzwiller method. The fluctuations by breathers explain the rapid decrease of the spin correlation function in short distances and give also low energy excited states with the symmetries and energetic ordering 3 B < 1 A < 1 B that are characte...
16 citations
TL;DR: In this article, the quantum translation and breather motions of spin density wave (SDW) solitons in the 1 2 -filled one-dimensional (1D) Hubbard model were calculated.
3 citations
TL;DR: In this article, the authors derived instability conditions for the normal paramagnetic (RHF) state and broken symmetry solutions of the extended Hubbard model including the nearest neighbour repulsion and the exchange interaction on a planar square lattice.
Abstract: This report describes instabilities of the normal paramagnetic (RHF) state and broken symmetry solutions of the extended Hubbard model including the nearest neighbour repulsion and the exchange interaction on a planar square lattice Based on the linear-response theory we derive instability conditions with ordering vector q = Q ≡ (π,π) and q = Q0 ≡ (0,0) which have definite symmetry properties For q = Q we obtain four non-magnetic states, a charge-density wave (CDW), a charge-current wave (CCW) and two bond-order waves (BOWs) and five magnetic states, an ordinary antiferromagnetism (AF), a spin-current wave (SCW), two axial-spin-bond-order waves (ASBOWs) and a helical-spin-bond-order wave (HSBOW) For q = Q0 it is shown that there are three states, a BOW, a ferromagnetism (FM) and a spin-bond-order wave (SBOW)