论文标题
多个悬浮粒子的最佳冷却:远场波沿形状理论
Optimal Cooling of Multiple Levitated Particles: Theory of Far-Field Wavefront-Shaping
论文作者
论文摘要
操纵小规模物体的机会使我们陷入了我们对物理学的理解的局限性。在这方面,特别有希望的是悬浮的跨学科领域,在该领域中,可以利用光场通过光学上悬浮它们来分离纳米粒子的环境。当朝着其运动量子基态冷却时,悬浮的系统提供了显示介观量子特性的诱人前景。目前,限于具有简单形状的单个对象,对悬浮的兴趣目前正朝着操纵更复杂的结构(例如具有多个颗粒或不同自由度的那些对象)迈进。不幸的是,当前的冷却技术主要是为单个对象设计的,因此无法轻易多重地解决此类耦合的多体系统。在这里,我们提出了一种基于远场中光的空间调制的方法,以平行冷却多个纳米对象。我们的程序基于实验可测量的散射矩阵以及随时间的变化。我们演示了如何从这些成分中构成线性换档算子,其本征态被确定为实现悬浮颗粒复杂移动集合的最有效冷却的传入波前。本文与Arxiv:2103.12592并行提交,提供了对预期冷却性能以及该方法对环境参数的鲁棒性的理论和数值研究。
The opportunity to manipulate small-scale objects pushes us to the limits of our understanding of physics. Particularly promising in this regard is the interdisciplinary field of levitation, in which light fields can be harnessed to isolate nano-particles from their environment by levitating them optically. When cooled down towards their motional quantum ground state, levitated systems offer the tantalizing prospect of displaying mesoscopic quantum properties. Currently restricted to single objects with simple shapes, the interest in levitation is currently moving towards the manipulation of more complex structures, such as those featuring multiple particles or different degrees of freedom. Unfortunately, current cooling techniques are mostly designed for single objects and thus cannot easily be multiplexed to address such coupled many-body systems. Here, we present an approach based on the spatial modulation of light in the far-field to cool down multiple nano-objects in parallel. Our procedure is based on the experimentally measurable scattering matrix and on its changes with time. We demonstrate how to compose from these ingredients a linear energy-shift operator, whose eigenstates are identified as the incoming wavefronts that implement the most efficient cooling of complex moving ensembles of levitated particles. Submitted in parallel with arxiv:2103.12592, this article provides a theoretical and numerical study of the expected cooling performance as well as of the robustness of the method against environmental parameters.