Exact Microscopic Calculation of Spin Wave Frequencies and Linewidths in the Two-Dimensional Heisenberg Antiferromagnet at Low Temperature
We present here exact results for the temperature dependent spin wave frequencies and damping in the 2-D Heisenberg antiferromagnet. Results for the 2-D ferromagnet have been presented previously.1 We use methods that were first developed in 1-D classical systems,2 where the dynamics at all wavelengths were obtained, and that have been used to discuss the 2-D antiferromagnet at T=0.3 We find that in 2-D, the longest wavelength behavior is not readily determined by these methods, and so we will restrict ourselves to wavelengths such that qξ>>1, where ξ is the coherence length.
KeywordsFrequency Shift Spin Wave Classical Limit Heisenberg Antiferromagnet Spin Wave Theory
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