Дата и время публикации : 1998-08-17T14:36:33Z
Авторы публикации и институты :
F. Bouis (LLB CEA-Saclay, France)
M. N. Kiselev (LLB CEA-Saclay, France, Kurchatov Institute, Moscow, Russia)
Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 7 pages, Proceedings of SCES98/Paris; one reference added
Первичная категория: cond-mat.str-el
Все категории : cond-mat.str-el
Краткий обзор статьи: In the partition function of the Kondo lattice, spin matrices are exactly replaced by bilinear combinations of Fermi operators with the purely imaginary chemical potential lambda=-i.pi.T/2 (Popov representation). This new representation of spin operators allows one to introduce new Green’s functions with Matsubara frequencies 2.pi.T(n+1/4) for S=1/2. A simple temperature diagram technique is constructed with the path integral method. This technique is standard and does not contain the complicated combinatoric rules characteristic of most of the known variants of the diagram techniques for spin systems. The effective action for the almost antiferromagnetic Kondo lattice is derived.