Perturbation theory by flow equations: dimerized and frustrated S=1/2 chain

被引：213

作者：

Knetter, C ^{[1
]}

Uhrig, GS ^{[1
]}

机构：

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

来源：

EUROPEAN PHYSICAL JOURNAL B | 2000年 / 13卷 / 02期

关键词：

D O I：

10.1007/s100510050026

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

The flow equation method (Wegner, 1994) is used as continuous unitary transformation to construct perturbatively effective Hamiltonians. The method is illustrated in detail for dimerized and frustrated antiferromagnetic S = 1/2 chains. The effective Hamiltonians conserve the number of elementary excitations which are S = 1 magnons for the dimerized chains. The sectors of different; number of excitations are clearly separated. Easy-to-use results for the gap, the dispersion and the ground state energies of the chains are provided.

引用

页码：209 / 225

页数：17

共 35 条

[11] NEW THEORY OF THE SPIN-PEIERLS TRANSITION WITH SPECIAL RELEVANCE TO THE EXPERIMENTS ON TTFCUBDT [J].

CROSS, MC ;

FISHER, DS .

PHYSICAL REVIEW B, 1979, 19 (01) :402-419

[12]

DOMB C, 1989, PHASE TRANSITIONS CR, V13

[13] Numerical evidence for multiplicative logarithmic corrections from marginal operators [J].

Eggert, S .

PHYSICAL REVIEW B, 1996, 54 (14) :R9612-R9615

[14] Reexamination of the microscopic couplings of the quasi-one-dimensional antiferromagnet CuGeO3 [J].

Fabricius, K ;

Klumper, A ;

Low, U ;

Buchner, B ;

Lorenz, T ;

Dhalenne, G ;

Revcolevschi, A .

PHYSICAL REVIEW B, 1998, 57 (02) :1102-1107

[15] Magnetic excitations in the S=1/2 alternating chain compound (VO)(2)P2O7 [J].

Garrett, AW ;

Nagler, SE ;

Tennant, DA ;

Sales, DA ;

Barnes, T .

PHYSICAL REVIEW LETTERS, 1997, 79 (04) :745-748

[16] PERTURBATION EXPANSIONS FOR QUANTUM MANY-BODY SYSTEMS [J].

GELFAND, MP ;

SINGH, RRP ;

HUSE, DA .

JOURNAL OF STATISTICAL PHYSICS, 1990, 59 (5-6) :1093-1142

[17] PERTURBATIVE RENORMALIZATION-GROUP FOR HAMILTONIANS [J].

GLAZEK, SD ;

WILSON, KG .

PHYSICAL REVIEW D, 1994, 49 (08) :4214-4218

[18] RENORMALIZATION OF HAMILTONIANS [J].

GLAZEK, SD ;

WILSON, KG .

PHYSICAL REVIEW D, 1993, 48 (12) :5863-5872

[19] SPONTANEOUS DIMERIZATION IN THE S=1/2 HEISENBERG ANTI-FERROMAGNETIC CHAIN WITH COMPETING INTERACTIONS [J].

HALDANE, FDM .

PHYSICAL REVIEW B, 1982, 25 (07) :4925-4928

[20] SINGULARITIES NEAR THE BIFURCATION POINT OF THE ASHKIN-TELLER MODEL [J].

KADANOFF, LP .

PHYSICAL REVIEW B, 1980, 22 (03) :1405-1408

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