论文标题
通过冷阻尼反馈的耦合机械谐振器链的多米诺冷却
Domino cooling of a coupled mechanical-resonator chain via cold-damping feedback
论文作者
论文摘要
我们提出了一种多米诺冷却方法，以通过在未解决的侧带机制中工作的光力机械腔来实现耦合机械谐振链的同时进行基础状态冷却。通过将第一个机械谐振器上的冷阻尼反馈与其他相邻的机械谐振器之间的最接近的邻接耦合相结合，可以实现这种多米诺效应冷却。我们获得了这些机械谐振器的有效敏感性，噪声光谱，最终平均声子数和冷却速率的分析结果，并找到了这些谐振器的最佳冷却条件。特别是，我们分析了两种机械谐振器的情况，并发现通过适当的工程激光功率或反馈，可以实现对称和非对称地面状态冷却之间的灵活开关。这可用于制备机械系统中的对称量子状态。我们还模拟了耦合的$ N $机械谐波链的冷却性能，并确认可以在未解决的侧带机制中同时将这些谐振器同时冷却至其量子基态。在适当的参数条件下，机械谐振链的冷却显示沿链的温度梯度。这项研究开辟了一条在不良腔体制中对多个机械谐振器进行量子操纵的途径。
We propose a domino-cooling method to realize simultaneous ground-state cooling of a coupled mechanical-resonator chain through an optomechanical cavity working in the unresolved-sideband regime. This domino-effect cooling is realized by combining the cold-damping feedback on the first mechanical resonator with nearest-neighbor couplings between other neighboring mechanical resonators. We obtain analytical results for the effective susceptibilities, noise spectra, final mean phonon numbers, and cooling rates of these mechanical resonators, and find the optimal-cooling condition for these resonators. Particularly, we analyze a two-mechanical-resonator case and find that by appropriately engineering either the laser power or the feedback, a flexible switch between symmetric and asymmetric ground-state cooling can be achieved. This could be used for preparing symmetric quantum states in mechanical systems. We also simulate the cooling performance of a coupled $N$-mechanical-resonator chain and confirm that these resonators can be simultaneously cooled to their quantum ground states in the unresolved-sideband regime. Under proper parameter conditions, the cooling of the mechanical-resonator chain shows a temperature gradient along the chain. This study opens a route to quantum manipulation of multiple mechanical resonators in the bad-cavity regime.
