Optical bistability in a low-photon-density regime
Optical bistability in a low-photon-density regime
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低光子密度区的光学双稳
DOI：
10.1103/physreva.98.043802
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发表时间：
2018-10-01
影响因子：
2.9
通讯作者：
Miyashita, Seiji
中科院分区：
文献类型：
--
作者：
Shirai, Tatsuhiko;Todo, Synge;Miyashita, Seiji
我们给出了光学双稳态的微观描述，其中传输系数作为输入光强度的函数具有两个不同的值，并且系统表现出带有磁滞回线的不连续跳跃。我们开发了一种有效的数值算法来处理许多光子和大量两能级原子混合系统的量子主方程。通过使用这种方法，我们从量子主方程的时间演化算子的本征模和本征值的角度来表征双稳定性。我们根据腔中的光子数密度对光学双稳态类型进行分类。与先前对高光子密度区域中光学双稳定性的研究相比，其中光子可以被视为经典电磁场并且共振光谱具有单峰结构，我们研究了低光子密度区域中光学双稳定性的性质，其中光子和原子自由度发生杂化并且共振光谱具有双峰结构。揭示后一种情况下光学双稳态的本质对于量子系统的操纵可能很重要。具体来说，我们讨论了光学双稳态的稳态特性：光子数密度对强度的依赖性以及双稳态区内光子数分布的双峰结构。至于动力学特性，我们发现弛豫时标随系统尺寸呈指数增长，并揭示了光学双稳态的磁滞回线如何取决于系统尺寸和驱动振幅的扫描速率。最后，通过研究输入场失谐频率的影响，我们阐明了低光子密度范围内当前光学双稳态的特征，这与标准光学双稳态现象有本质上的不同。
We give a microscopic description of the optical bistability, where the transmission coefficient has two different values as a function of input light intensity, and the system exhibits a discontinuous jump with a hysteresis loop. We developed an efficient numerical algorithm to treat the quantum master equation for hybridized systems of many photons and a large number of two-level atoms. By using this method, we characterize the bistability from the viewpoint of eigenmodes and eigenvalues of the time-evolution operator of the quantum master equation. We classify types of optical bistability according to the photon number density in the cavity. In contrast to previous studies of optical bistability in the high-photon-density regime where the photons can be treated as a classical electromagnetic field and the resonance spectrum has a single-peak structure, we study the nature of optical bistability in the low-photon-density regime where the hybridization of photon and atom degrees of freedom occurs and the resonance spectrum has a double-peak structure. Unraveling the nature of the optical bistability in the latter regime may be important for the manipulation of quantum systems. Concretely, we discuss the steady-state properties of the optical bistability: dependencies of the photon number density on the intensity and the double-peak structure of the photon number distribution inside the bistable region. As for the dynamical properties, we find that the relaxation timescale shows an exponential growth with the system size and reveal how the hysteresis loop of the optical bistability depends on the size of the system and the sweeping rate of the driving amplitude. Finally, by investigating the effects of detuning frequency of the input field, we clarify the characteristic properties of the present optical bistability within the low-photon-density regime, which are qualitatively different from the standard optical bistable phenomena.