RQC Seminar

216th RQC Seminar

• Speaker

  Mr. Yan Ke-Xiong
  ( Fuzhou University, China )

• Date

  16:00-17:00 (4:00 p.m. - 5:00 p.m.), August 14, 2025 (Thursday)

• Venue

  Hybrid(ZOOM・ Wako Main Research Bldg. 3F 345-347 Seminar Room / 研究本館3階 セミナー室 (345-347) (C01))

• Title

  Spontaneous Emission in Casimir-Rabi Oscillations through a Week Optomechanical Couplin

• Inquiries

  rqc_info[at]ml.riken.jp

Abstract
This report focuses on n-photon/n-phonon emission in Casimir-Rabi oscillations with dissipative channels. When the mechanical oscillator is initially in an excited state, its free evolution, driven by the dynamical Casimir effect (DCE), leads to the generation of radiation in the vacuum, analogous to the spontaneous emission of an excited atom [1]. In the regime where the loss rates are lower than the corresponding frequency splittings, reversible energy exchange can occur between the excited mechanical oscillator and the vacuum cavity field (i.e. vacuum Casimir-Rabi oscillations). By using the quantum trajectory approach, we show that n-photon/n-phonon emission can be achieved by opening dissipative channels for these Casimir-Rabi oscillations [2-4]. Simulation results from10^5quantum trajectories demonstrate that the purities of two-photon emission, two-phonon emission, and three-phonon emission can reach 0.92, 0.94, and 0.95, respectively. These values are observed in Casimir-Rabi oscillations between the three-phonon state and the two-photon state in a weak optomechanical coupling. The coupling between these two states ensures that the mechanical frequency is lower than the optical frequency, while maintaining a large effective coupling strength, which facilitates the experiment. This n-photon/n-phonon phenomenon could provide insights into the physical characteristics of photon and phonon emission in the DCE.