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arXiv · 0708.1272

Spin-wave spectra of a kagome stripe

A. Donkov·A. V. Chubukov
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Abstract

We study ground state degeneracy and spin-wave excitations in a 1D version of a Kagome antiferromagnet -- a Heisenberg antiferromagnet on a Kagome stripe. We show that for nearest-neighbor interaction, the classical ground state is infinitely degenerate. For any spin configuration from the degenerate set, the classical spin-wave spectrum contains, in addition to Goldstone modes, a branch of zero energy excitations, and a zero mode in another branch. We demonstrate that the interactions beyond nearest neighbors lift the degeneracy, eliminate a zero mode, and give a finite dispersion to formerly zero-energy branch, leaving only Goldstone modes as zero-energy excitations.

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A. Donkov, A. V. Chubukov. 2007-08-09. Spin-wave spectra of a kagome stripe. https://doi.org/10.1209/0295-5075/80/67005

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