Low-energy singlets in the Heisenberg antiferromagnet on the kagomé lattice
The spin-1/2 Heisenberg antiferromagnet on the kagomé lattice, is mapped by contractor renormalization to a spin-pseudospin Hamiltonian on the triangular superlattice. Variationally, we find a ground state with columnar dimer order. Dimer orientation fluctuations are described by an effective O(2) m...
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| Published in | Physical review letters Vol. 93; no. 18; p. 187205 |
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| Main Authors | , |
| Format | Journal Article |
| Language | English |
| Published |
United States
29.10.2004
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| Online Access | Get more information |
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| Summary: | The spin-1/2 Heisenberg antiferromagnet on the kagomé lattice, is mapped by contractor renormalization to a spin-pseudospin Hamiltonian on the triangular superlattice. Variationally, we find a ground state with columnar dimer order. Dimer orientation fluctuations are described by an effective O(2) model at energies above an exponentially suppressed clock mass scale. Our results explain the large density of low-energy singlets observed numerically, and the nonmagnetic T2 specific heat observed experimentally. |
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| ISSN: | 0031-9007 |
| DOI: | 10.1103/physrevlett.93.187205 |