Atomic self-ordering to a crystalline phase in optical resonators is a consequence of the intriguing nonlinear dynamics of strongly coupled atom motion and photons. Generally the resulting phase diagrams and atomic states can be largely understood on a mean-field level. However, close to the phase transition point, quantum fluctuations and atom-field entanglement play a key role and initiate the symmetry breaking. Here we propose a modified ring cavity geometry, in which the asymmetry imposed by a tilted pump beam reveals clear signatures of quantum dynamics even in a larger regime around the phase transition point. Quantum fluctuations become visible both in the dynamic and steady-state properties. Most strikingly we can identify a regime where a mean-field approximation predicts a runaway instability, while in the full quantum model the quantum fluctuations of the light field modes stabilize uniform atomic motion. The proposed geometry thus allows to unveil the "quantumness" of atomic self-ordering via experimentally directly accessible quantities.

中文翻译：

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揭示环形腔中原子自定序的量子性质。

光学共振器中对晶相的原子自定序是强耦合原子运动和光子的有趣非线性动力学的结果。通常，可以在平均场水平上大致了解所得的相图和原子态。然而，在相变点附近，量子涨落和原子场纠缠起着关键作用，并引发对称性破坏。在这里，我们提出了一种改进的环形腔几何结构，其中倾斜的泵浦光束强加的不对称性揭示了量子动力学的清晰特征，即使在相变点附近的较大范围内也是如此。量子涨落在动态和稳态特性中都变得可见。最惊人的是，我们可以确定一种均值场近似预测失控失稳的状态，而在全量子模型中，光场模的量子涨落稳定了均匀的原子运动。因此，提出的几何形状允许通过实验上直接可访问的量揭示原子自我排序的“量子”。