{
  "id": "2303.08547",
  "version": "v1",
  "published": "2023-03-15T12:02:27.000Z",
  "updated": "2023-03-15T12:02:27.000Z",
  "title": "Simultaneous Quantum Squeezing of Light Polarizations and Atomic Spins in a Cold Atomic Gas",
  "authors": [
    "Jinzhong Zhu",
    "Yue Mu",
    "Guoxiang Huang"
  ],
  "categories": [
    "quant-ph",
    "physics.optics"
  ],
  "abstract": "We present a scheme to realize simultaneous quantum squeezing of light polarizations and atomic spins via a perturbed double electromagnetically induced transparency (DEIT) in a cold four-level atomic ensemble coupled with a probe laser pulse of two polarization components. We derive two coupled quantum nonlinear Schr\\\"odinger equations from Maxwell-Heisenberg-Langevin equations describing the quantum dynamics of the atoms and the probe pulse, and develop a quantum theory of vector optical soliton (VOS), which have ultraslow propagation velocity and extremely low generation power. We solve the non-Hermitian eigenvalue problem describing the quantum fluctuations on the background of the VOS, and rigorously prove that all fluctuation eigenmodes (including continuous modes and four zero modes) obtained constitute a bi-orthonormal and complete set. We find that, due to the giant self- and cross-Kerr nonlinearities contributed by the perturbed DEIT, a large polarization squeezing of the probe pulse can be realized. We also find that, together with the polarization squeezing of the probe pulses, a significant squeezing of atomic spins also occurs simultaneously. The results of the simultaneous squeezing of light polarizations and atomic spins by using only a coherent probe pulse reported here opens a route for uncovering the unique property of the quantum interface between light and atomic ensembles, and also for applications in quantum information and precision measurement.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-03-15T12:02:27.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "atomic spins",
      "cold atomic gas",
      "light polarizations",
      "simultaneous quantum squeezing",
      "probe pulse"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}