Spin-liquid ground state in a two-dimensional nonfrustrated spin model

被引：47

作者：

Santoro, G ^{[1
]}

Sorella, S

Guidoni, L

Parola, A

Tosatti, E

机构：

[1] Ist Nazl Fis Mat, Trieste, Italy

[2] SISSA, Trieste, Italy

[3] Univ Milan, Como, Italy

[4] Ist Nazl Fis Mat, Como, Italy

[5] Abdus Salaam Int Ctr Theoret Phys, Trieste, Italy

来源：

PHYSICAL REVIEW LETTERS | 1999年 / 83卷 / 15期

关键词：

D O I：

10.1103/PhysRevLett.83.3065

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We consider an exchange model describing two isotropic spin-1/2 Heisenberg antiferromagnets coupled by a quartic term on the square lattice. The model is relevant for systems with orbital degeneracy and strong electron-vibron coupling in the large Hubbard repulsion limit, and is known to show a spin-Peierls-like dimerization in one dimension. In two dimensions we calculate energy gaps, susceptibilities, and con elation functions with a Green's function Monte Carlo method. We find a finite tripler and singlet gap, with no evidence of order of any kind. We conclude that the ground state is, most likely, a spin liquid of resonating valence bonds.

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页码：3065 / 3068

页数：4

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