Sd-model with strong exchange coupling and a metal-insulator phase transition

• Дата: 2006
• Автори: Izyumov, Yu.A., Chaschin, N.I., Alexeev, D.S.
• Формат: Стаття
• Мова: English
• Опубліковано: Інститут фізики конденсованих систем НАН України 2006
• Назва видання: Condensed Matter Physics
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/121358
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Цитувати: Sd-model with strong exchange coupling and a metal-insulator phase transition / Yu.A. Izyumov, N.I. Chaschin, D.S. Alexeev // Condensed Matter Physics. — 2006. — Т. 9, № 3(47). — С. 545–555. — Бібліогр.: 9 назв. — англ.

Sd-exchange model (Kondo lattice model) is formulated for strong sd-coupling within the framework of the Xoperators technique and the generating functional approach. The X-operators are constructed based on the exact eigen functions of a single-site sd-exchange Hamiltonian. Such representation enables us to develop a perturbation theory near the atomic level. A locator-type representation was derived for the electron Green’s function. The electron self-energy includes interaction of electrons and spin fluctuations. An integral equation for the self-energy was obtained in the limit of infinite localized spins. A solution of this equation in the static approximation for spin fluctuations leads to a structure of electron Green’s function showing a metal-insulator phase transition. This transition is similar to that in the Hubbard model at half filling.