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Low temperature spin diffusion in the one-dimensional quantum $O(3)$ nonlinear $σ$-model

Subir Sachdev·Kedar Damle
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Abstract

An effective, low temperature, classical model for spin transport in the one-dimensional, gapped, quantum $O(3)$ non-linear $σ$-model is developed. Its correlators are obtained by a mapping to a model solved earlier by Jepsen. We obtain universal functions for the ballistic-to-diffusive crossover and the value of the spin diffusion constant, and these are claimed to be exact at low temperatures. Implications for experiments on one-dimensional insulators with a spin gap are noted.

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Subir Sachdev, Kedar Damle. 1996-10-15. Low temperature spin diffusion in the one-dimensional quantum $O(3)$ nonlinear $σ$-model. https://doi.org/10.1103/physrevlett.78.943

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