量子光场与高频光机械振子相互作用机理及其精密测量应用研究

Optomechanical system is of importance to realize small displacement measurement, which can be extended for high precision measurements of acceleration and weak magnetic field. In recent years, displacement measurement exceeding the standard quantum limit has been realized in superconducting microwave and superconducting drum coupling system. However, it is limited for further development and applications because the quantum state control in microwave region is extremely difficult, and the low frequency mechanical resonator is hard to keep its quantum ground state. Here we will study the interaction between 1550 nm quantum photons and high frequency mechanical resonators, based on our previous studies and our low temperature skills. We will realize the quantum squeezing states of the mechanical modes and study the precision measurement by evading quantum backaction forces in multi-mode and multi-resonator systems. We will also study the side band cooling beyond quantum noise limit using photon squeezing states and through multi-pathway or high dimentional photon entangled states, and further exceed the standard quantum limit in displacement measurements. This program will help to promote the development of small displacement measurement in our country, and will train a number of talented in the field of optomechanical quantum precision measurement, also we will realize the international leading level of noise compression and break through the standard quantum limit in precision measurements.

光机械体系是实现微小位移测量的重要体系之一，通过微小位移测量可以间接实现加速度、弱磁场等重要物理量的高精密测量。近年来国际上利用超导微波腔和超导薄膜机械振子已经实现了超越标准量子极限的位移测量。然而微波量子态操控难度大、低频机械振子量子基态难制备等因素限制了该领域的进一步发展和应用。本项目拟在前期的重要研究基础上，通过极低温技术手段直接将高频谐振子制备到量子基态，深入研究1550纳米波段的量子光场与高频机械振子相互作用，实现谐振模式的量子压缩态；并利用多模、多机械振子耦合系统实现规避量子反作用的精密测量方案；利用压缩光场、多光子路径纠缠态、高维光子纠缠态等量子光场实现超越量子噪声极限的边带冷却和超越标准量子极限的位移测量。本项目的实施将有助于提升我国在微小位移测量方面的研究实力，培养一批在光机械量子精密测量领域的后备人才，实现国际领先水平的噪声压缩和突破标准量子极限的精密测量。

光机械体系是实现微小位移测量的重要体系之一，通过微小位移测量可以间接实现加速度、弱磁场等重要物理量的高精密测量。近年来国际上利用超导微波腔和超导薄膜机械振子已经实现了超越标准量子极限的位移测量。然而微波量子态操控难度大、低频机械振子量子基态难制备等因素限制了该领域的进一步发展和应用。本项目在前期的重要研究基础上，在多模耦合机械振子体系中实现了机械模式的热噪声双模压缩态；在10 mK量级的极低温环境下，研究了通信波段光子（约1550 nm波长）与约5 GHz频率机械振子的相互作用，耦合强度约1 MHz，实现了少声子机械模式的测量；实现了多模振子声子频梳的产生和测量，实现多机械振子的串联耦合，并利用多个耦合机械振子研究了辐射热计精密测量方案；开展了纯态单光子源的制备和操控研究，实现了纠缠光源的制备，以及NOON型量子干涉仪的频域可分辨测量。这些结果为后期利用高频机械模式量子态进行精密测量奠定了基础，也可能在基于光机系统的量子换能器界面发挥作用，为构造基于机械模式的量子网络节点提供支撑作用。