Two-fluid model of a Bose-Einstein condensate in the cavity optomechanical regime

光机械共振下坏光学腔中玻色-爱因斯坦凝聚体的动力学相

Dynamical phases of a BEC in a bad optical cavity at optomechanical resonance

本研究通过微扰论和数值模拟，揭示了光机械共振附近玻色-爱因斯坦凝聚体在坏腔中的动力学相，包括混沌相和极限环相，并指出非绝热修正对捕捉这些相的关键作用。

Excitations of optomechanically driven Bose-Einstein condensates in a cavity: photodetection measurements

We present a detailed study to analyse the Dicke quantum phase transition within the thermodynamic limit for an optomechanically driven Bose-Einstein condensates in a cavity. The photodetection-based quantum optical measurements have been performed to study the dynamics and excitations of this optomechanical Dicke system. For this, we discuss the eigenvalue analysis, fluorescence spectrum and the homodyne spectrum of the system. It has been shown that the normal phase is negligibly affected by the mechanical mode of the mirror while it has a significant effect in the superradiant phase. We hav…

Classical dynamics of the optomechanical modes of a Bose-Einstein condensate in a ring cavity

We consider a cavity optomechanical system consisting of a Bose-Einstein condensate (BEC) interacting with two counterpropagating traveling-wave modes in an optical ring cavity. In contrast to the more familiar case where the condensate is driven by the standing-wave field of a high-$Q$ Fabry-P{é}rot cavity we find that both symmetric and antisymmetric collective density side modes of the BEC are mechanically excited by the light field. In the semiclassical, mean-field limit where the light field and the zero-momentum mode of the condensate are treated classically the system is found to exhibi…

Dynamical Casimir Effect in Superradiant Light Scattering by Bose-Einstein Condensate in an Optomechanical Cavity

We investigate the effects of dynamical Casimir effect in superradiant light scattering by Bose-Einstein condensate in an optomechanical cavity. The system is studied using both classical and quantized mirror motions. The cavity frequency is harmonically modulated in time for both the cases. The main quantity of interest is the number of intracavity scattered photons. The system has been investigated under the weak and strong modulation. It has been observed that the amplitude of the scattered photons is more for the classical mirror motion than the quantized mirror motion. Also, initially, th…

Dynamical Phase Transition of two-component Bose-Einstein condensate with nonlinear tunneling in an optomechanical cavity-mediated double-well system

We investigate the dynamical phase transition of two-component Bose-Einstein condensate with nonlinear tunneling, which is trapped inside a double-well and dispersively coupled to a single mode of a high-finesse optical cavity with one moving end mirror driven by a single mode standing field. The nonlinear tunneling interaction leads to an increase of stability points and riches the phase diagram of the system. It is shown that the appearance of the moving end mirror speeds up the tunneling of Bose-Einstein condensates, which makes population difference between two wells and regulates the numb…

Back-action-free quantum optomechanics with negative-mass Bose-Einstein condensates

We propose that the dispersion management of coherent atomic matter waves can be exploited to overcome quantum back-action in condensate-based optomechanical sensors. The effective mass of an atomic Bose-Einstein condensate modulated by an optical lattice can become negative, resulting in a negative-frequency optomechanical oscillator, a negative environment temperature, and optomechanical properties opposite to those of a positive-mass system. This enables a quantum-mechanics-free subsystem insulated from quantum back-action.