Symmetries and triplet dispersion in a modified Shastry-Sutherland model for SrCu2(BO3)2

被引：13

作者：

Knetter, C ^{[1
]}

Müller-Hartmann, E ^{[1
]}

Uhrig, GS ^{[1
]}

机构：

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

来源：

JOURNAL OF PHYSICS-CONDENSED MATTER | 2000年 / 12卷 / 42期

关键词：

D O I：

10.1088/0953-8984/12/42/312

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

We investigate the one-triplet dispersion in a modified Shastry-Sutherland model for SrCu2(BO3)(2) by means of a series expansion about the limit of strong dimerization. Our perturbative method is based on a continuous unitary transformation that maps the original Hamiltonian to an effective, energy-quanta-conserving block diagonal Hamiltonian H-eff. The dispersion splits into two branches which are nearly degenerate. We analyse thr symmetries of the model and show that space group operations are necessary to explain the degeneracy of the dispersion at k = 0 and at the border of the magnetic Brillouin zone. Moreover, we investigate the behaviour of the dispersion for small /k/ and compare our results to inelastic neutron scattering data.

引用

页码：9069 / 9083

页数：15

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