Next-generation ultralow-noise mechanical sensors defined and controlled by light

机械技术在社会中无处不在，从计时设备中的振荡器到汽车和手机中的加速度计和电子滤波器。它们也代表了基础科学和应用科学不可或缺的工具：使用微小的机械系统，可以在原子尺度上“感受”表面，以单质子分辨率检测化学质量变化，并从纳米级原子核簇中感知元素特定的磁性“牵引”（甚至创建3d地图）。在光力学领域，我们已经学会了利用光施加的力，在所有尺寸范围内对这些系统进行前所未有的控制，从而为下一代传感器带来全新的功能，包括量子力学定律发挥核心作用的传感器。 我们的研究旨在实现超低噪声微机械传感器，这些传感器以独特的方式重新配置和控制。为此，我们制造了精致的“微型蹦床”，展示了世界纪录的力敏感性和光学性能的结合，这样，来自平均一个光子的辐射力-自然界允许的最小光量-将对其机械轨迹产生深远的影响。在这里，我们建议利用这一突破来展示强大的单光子控制，访问量子运动状态，并产生可用于增强干涉仪（例如用于检测引力波的干涉仪）的量子“压缩”光。此外，通过部分悬浮相关的机械元件，我们将进一步提高它们的灵敏度，基本上用光代替它们的主要机械支撑（柔性材料的低噪音替代品）。最后，我们将追求一个质的新系统，其中光强烈地控制振荡质量的空间分布：通过光学扰动周期性结构（“声子晶体”），我们可以在原位将振荡质量的空间范围从厘米尺度平滑地调整到微米尺度-这是目前闻所未闻的控制水平。此外，由于集体增强效应，预计较大的器件对给定量的光（尽管其质量较大）表现出较大的响应，从而能够对芯片级器件中的单光子光水平产生真正的宏观响应。除了创造新型的可重构机械感测技术之外，这些互补的努力还建立在宏观尺度上的量子运动的基础研究、各种“量子比特”（“qubit”）技术与光（例如，用于长距离量子保密通信），以及探测zeptonewton力（相当于相隔100公里的两条面包之间的引力）。

Mechanical technologies are everywhere in society, from oscillators in timekeeping devices to accelerometers and electronic filters in automobiles and cell phones. They also represent an indispensable tool for fundamental and applied science: using tiny mechanical systems, it is possible to "feel around" surfaces at the atomic scale, detect chemical mass changes with single-proton resolution, and sense element-specific magnetic "tugs" from nanoscale clusters of nuclei (even creating a 3d map). In the field of optomechanics, we have learned to exploit the forces exerted by light to gain an unprecedented level of control over these systems at all size scales, leading to entirely new functionalities for next-generation sensors, including those in which the laws of quantum mechanics play a central role. Our research aims to realise ultralow-noise micromechanical sensors that are reconfigured and controlled by light in unique ways. To this end, we fabricate delicate "micro-trampolines" exhibiting a world-record combination of force sensitivity and optical performance, such that the radiation force from an average of just one photon -- the smallest quantity of light allowed by nature -- will exert a profound influence over their mechanical trajectories. Here we propose to capitalise upon this breakthrough to demonstrate strong single-photon control, access quantum states of motion, and generate quantum "squeezed" light useful for enhancing interferometers (such as those used to detect gravitational waves). Additionally, by partially levitating related mechanical elements, we will even further enhance their sensitivities by essentially replacing their primary mechanical supports with light (a low-noise alternative to flexible materials). Finally, we will pursue a qualitatively new system in which light strongly controls the spatial distribution of oscillating mass: by optically perturbing a periodic structure ("phononic crystal"), we can smoothly tune the spatial extent of oscillating mass from the centimetre scale to the micron scale in situ -- a level of control that is currently unheard of. Furthermore, due to a collective enhancement effect, a larger device is predicted to exhibit a larger response to a given quantity of light (despite its larger mass) enabling a truly macroscopic response to single-photon light levels in a chip-scale device. In addition to creating new types of reconfigurable mechanical sensing technologies, these complementary efforts build toward fundamental studies of quantum motion at the macro scale, mechanical transduction of quantum information between a variety of "quantum bit" ("qubit") technologies and light (e.g., for long-distance quantum-secured communication), and the detection of zeptonewton forces (equivalent to the gravitational pull between two loaves of bread separated by 100 km).