• Corpus ID: 90262560

Maximum Spontaneous Magnetization and Nambu-Goldstone Mode

  title={Maximum Spontaneous Magnetization and Nambu-Goldstone Mode},
  author={Tohru Koma},
  journal={arXiv: Mathematical Physics},
  • T. Koma
  • Published 25 December 2017
  • Physics
  • arXiv: Mathematical Physics
We study quantum antiferromagnetic Heisenberg models on a hypercubic lattice. We prove the following three theorems without any assumption: (i) The spontaneous magnetization which is obtained by applying the infinitesimally weak symmetry breaking field is equal to the maximum spontaneous magnetization at zero or non-zero low temperatures. (ii) When the spontaneous magnetization is non-vanishing at zero temperature, there appears a gapless excitation, Nambu-Goldstone mode, above an infinite… 
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