{
  "id": "2308.16204",
  "version": "v1",
  "published": "2023-08-29T21:34:22.000Z",
  "updated": "2023-08-29T21:34:22.000Z",
  "title": "Four interacting spins: addition of angular momenta, spin-spin correlation functions, and entanglement",
  "authors": [
    "Raimundo R. dos Santos",
    "Lucas Alves Oliveira",
    "Natanael C. Costa"
  ],
  "comment": "10 pages, 5 figures",
  "categories": [
    "quant-ph"
  ],
  "abstract": "We study four spins on a ring coupled through competing Heisenberg interactions between nearest neighbors, $J$, and next-nearest neighbors, $J_2\\equiv\\alpha J>0$. The spectrum is obtained in a simple way by using the rules for addition of 4 angular momenta. This allows us to follow the evolution of the ground state with $\\alpha$, characterized by level crossings and by analyses of spin-spin correlation functions. Further insight is obtained by examining the entanglement between different parts of the system: we observe that the entanglement entropy is strongly dependent on how the system is partitioned.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-08-29T21:34:22.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "spin-spin correlation functions",
      "angular momenta",
      "interacting spins",
      "entanglement entropy",
      "competing heisenberg interactions"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}