Elementary excitations in the Hubbard model.

A. Vedyayev, В. А. Иванов

A. Vedyayev, M. Ye. Zhuravlev, В.А. Иванов

M. Yu. Nikolaev, Natalia Ryzhanova, A. Vedyayev +1 more

M. Yu. Nikolaev, Natalia Ryzhanova, A. Vedyayev +1 more

Abstract Two pecularities of diagram technique for Hubbard operators are established. Fermi‐type excitations for the Hubbard model with strong Coulomb repulsion are investigated with the help of this technique. The cause of ferromagnetism in the Hubbard model is discovered. Bose‐type elementary excitations are investigated and the region of existence of ferromagnetic ground state is obtained.

Hitoshi Asakawa, Masuo Suzuki

Elementary excitations in the one-dimensional Hubbard model with boundaries are discussed at the half-filling and without external magnetic fields. The energy of the present model is evaluated in the low-lying excited state, where there exist quasiparticles corresponding to elementary excitations in the charge and the spin sectors. The boundary scattering matrix of the quasiparticles is evaluated.

G. Uimin, С. В. Фомичев