{
  "id": "2302.09271",
  "version": "v1",
  "published": "2023-02-18T09:37:45.000Z",
  "updated": "2023-02-18T09:37:45.000Z",
  "title": "Entangling dynamics from effective rotor/spin-wave separation in U(1)-symmetric quantum spin models",
  "authors": [
    "Tommaso Roscilde",
    "Tommaso Comparin",
    "Fabio Mezzacapo"
  ],
  "comment": "5+3 pages, 3+2 figures",
  "categories": [
    "quant-ph",
    "cond-mat.stat-mech",
    "cond-mat.str-el"
  ],
  "abstract": "The non-equilibrium dynamics of quantum spin models is a most challenging topic, due to the exponentiality of Hilbert space; and it is central to the understanding of the many-body entangled states that can be generated by state-of-the-art quantum simulators. A particularly important class of evolutions is the one governed by U(1) symmetric Hamiltonians, initialized in a state which breaks the U(1) symmetry -- the paradigmatic example being the evolution of the so-called one-axis-twisting (OAT) model, featuring infinite-range interactions between spins. In this work we show that the dynamics of the OAT model can be closely reproduced by systems with power-law-decaying interactions, thanks to an effective separation between the zero-momentum degrees of freedom, associated with the so-called Anderson tower of states, and reconstructing a OAT model; and finite-momentum ones, associated with spin-wave excitations. This mechanism explains quantitatively the recent numerical observation of spin squeezing and Schr\\\"odinger-cat generation in the dynamics of dipolar Hamiltonians; and it paves the way for the extension of this observation to a much larger class of models of immediate relevance for quantum simulations.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-02-18T09:37:45.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "quantum spin models",
      "effective rotor/spin-wave separation",
      "entangling dynamics",
      "oat model",
      "state-of-the-art quantum simulators"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 3,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}