{
  "id": "quant-ph/9911061",
  "version": "v1",
  "published": "1999-11-15T02:57:05.000Z",
  "updated": "1999-11-15T02:57:05.000Z",
  "title": "Time dynamics in chaotic many-body systems: can chaos destroy a quantum computer?",
  "authors": [
    "V. V. Flambaum"
  ],
  "comment": "9 pages, RevTex",
  "categories": [
    "quant-ph",
    "chao-dyn",
    "cond-mat.mes-hall",
    "cond-mat.stat-mech",
    "nlin.CD",
    "nucl-th",
    "physics.atom-ph"
  ],
  "abstract": "Highly excited many-particle states in quantum systems (nuclei, atoms, quantum dots, spin systems, quantum computers) can be ``chaotic'' superpositions of mean-field basis states (Slater determinants, products of spin or qubit states). This is a result of the very high energy level density of many-body states which can be easily mixed by a residual interaction between particles. We consider the time dynamics of wave functions and increase of entropy in such chaotic systems. As an example we present the time evolution in a closed quantum computer. A time scale for the entropy S(t) increase is t_c =t_0/(n log_2{n}), where t_0 is the qubit ``lifetime'', n is the number of qubits, S(0)=0 and S(t_c)=1. At t << t_c the entropy is small: S= n t^2 J^2 log_2(1/t^2 J^2), where J is the inter-qubit interaction strength. At t > t_c the number of ``wrong'' states increases exponentially as 2^{S(t)} . Therefore, t_c may be interpreted as a maximal time for operation of a quantum computer, since at t > t_c one has to struggle against the second law of thermodynamics. At t >>t_c the system entropy approaches that for chaotic eigenstates.",
  "revisions": [
    {
      "version": "v1",
      "updated": "1999-11-15T02:57:05.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "quantum computer",
      "chaotic many-body systems",
      "time dynamics",
      "chaos destroy",
      "high energy level density"
    ],
    "note": {
      "typesetting": "RevTeX",
      "pages": 9,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 510249,
      "adsabs": "1999quant.ph.11061F"
    }
  }
}