Cumulant expansion for systems with large spins

被引：15

作者：

Kladko, K

Fulde, P

Garanin, DA

机构：

[1] Univ Calif Los Alamos Natl Lab, Condensed Matter Phys Grp, Los Alamos, NM 87545 USA

[2] Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Div Theoret, Los Alamos, NM 87545 USA

[3] Max Planck Inst Phys Komplexer Syst, D-01187 Dresden, Germany

来源：

EUROPHYSICS LETTERS | 1999年 / 46卷 / 04期

关键词：

D O I：

10.1209/epl/i1999-00104-y

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

A method is proposed for obtaining a systematic expansion of thermodynamic functions of spin systems with large spin S in powers of 1/S. It uses the cumulant technique and a coherent-state representation of the partition function Z. The expansion of Z in terms of cumulants yields an effective classical I Hamiltonian with temperature-dependent quantum corrections. For the Heisenberg quantum Hamiltonian, they have a non-Heisenberg form. The effective Hamiltonian can be solved by methods familiar for classical systems.

引用

页码：425 / 430

页数：6