The structure of operators in effective particle-conserving models

被引：106

作者：

Knetter, C ^{[1
]}

Schmidt, KP ^{[1
]}

Uhrig, GS ^{[1
]}

机构：

[1] Univ Cologne, Inst Theoret Phys, D-50937 Cologne, Germany

来源：

JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL | 2003年 / 36卷 / 29期

关键词：

D O I：

10.1088/0305-4470/36/29/302

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

For many-particle systems defined on lattices we investigate the global structure of effective Hamiltonians and observables obtained by means of a suitable basis transformation. We study transformations which lead to effective Hamiltonians conserving the number of excitations. The same transformation must be used to obtain effective observables. The analysis of the structure shows that effective operators give rise to a simple and intuitive perspective on the initial problem. The systematic calculation of n-particle irreducible quantities becomes possible constituting a significant progress. Details on how to implement the approach perturbatively for a large class of systems are presented.

引用

页码：7889 / 7907

页数：19

共 30 条

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