One Spin-Polaron Problem in the Two-Dimensional Kondo-Lattice

Дата и время публикации : 1997-05-26T07:55:17Z

Авторы публикации и институты :
L. A. Maksimov (Kurchatov Institute, Moscow)
A. F. Barabanov (Institute for High Pressure Physics, Troitsk)
R. O. Kuzian (Institute for Materials Science, Kiev)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 7 pages, revtex, 4 figures, to be published in Phys.Lett.A
Первичная категория: cond-mat.str-el

Все категории : cond-mat.str-el

Краткий обзор статьи: Within the frameworks of spin-polaron concept and the spherically symmetric state for the antiferromagnetic spin background, the one-particle motion is studied for two-dimensional Kondo-lattice. The elemetary excitations are represented as a Bloch superposition of four one-site electron states: two local states- a bare electron state and a local spin-polaron of small radius, and two states of delocalized polarons which correspond to the coupling of local states to the antiferromagnetic spin wave with momentum Q=(pi,pi), so called Q-polarons. As a remarkable result we show that the lowest band of elementary excitations is essentially determined by Q-polaron states in strongly coupled regime. The account of Q-polarons shifts the band bottom from (pi,pi) to (0,0). The spectral weight of a bare particle in the lowest band states can greatly differ from 1. This may lead to a large Fermi surface for relatively small particle concentration.

Category: Physics