TY - JOUR
T1 - Spin-wave spectra of a Kagome stripe
AU - Donkov, A.
AU - Chubukov, A. V.
PY - 2007/12/1
Y1 - 2007/12/1
N2 - 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.
AB - 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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U2 - 10.1209/0295-5075/80/67005
DO - 10.1209/0295-5075/80/67005
M3 - Article
AN - SCOPUS:77954768085
SN - 0295-5075
VL - 80
JO - EPL
JF - EPL
IS - 6
M1 - 67005
ER -