Interaction Corrections to Spin-Wave Theory in the Large-S Limit of the Quantum Heisenberg Ferromagnet

  title={Interaction Corrections to Spin-Wave Theory in the Large-S Limit of the Quantum Heisenberg Ferromagnet},
  author={Niels Benedikter},
  journal={Mathematical Physics, Analysis and Geometry},
  • Niels Benedikter
  • Published 9 April 2016
  • Physics
  • Mathematical Physics, Analysis and Geometry
The Quantum Heisenberg Ferromagnet can be naturally reformulated in terms of interacting bosons (called spin waves or magnons) as an expansion in the inverse spin size. We calculate the first order interaction correction to the free energy, as an upper bound in the limit where the spin size S∞8$S \to \infty $ and ßS is fixed (ß being the inverse temperature). Our result is valid in two and three spatial dimensions. We extrapolate our result to compare with Dyson’s low-temperature expansion… 

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