如何超越标准量子极限成为当今量子精密测量领域的核心问题之一。基于超冷里德堡原子的新型原子相互作用调控方法─里德堡缀饰─被提出并得到广泛关注。里德堡缀饰是指利用激光场耦合原子基态与里德堡态，激光频率与里德堡态跃迁失谐较大，使得基态原子混入少量里德堡态成分并产生频移，形成里德堡缀饰态。对于里德堡缀饰态原子，特殊激光与里德堡原子耦合形成长程和光场可控的新型原子相互作用，产生自旋压缩进而达到突破标准量子极限。与其它产生自旋压缩相比，里德堡缀饰具有容易控制且无需增加光腔的优点。我们从实验和理论模拟两方面同时对超冷里德堡原子体系（铷87）进行量子精密测量的关键科学与技术问题研究：完善超冷里德堡原子气体量子精密测量实验与理论模拟平台，研究里德堡原子气体中的里德堡缀饰和自旋压缩，并应用里德堡缀饰自旋压缩到原子钟时间频率基准，为进一步提高原子钟频率稳定度以及原子传感器的极限测量精度提供新的强有力的技术。

Nowadays, it is becoming one of the key factors to improve the resolution beyond the standard quantum limit and approaching the fundamental Heisenberg limit for quantum-enhanced precision measurement and sensing. Recent years, a new method called Rydberg dressing was proposed for manipulating atomic interactions based on ultra-cold Rydberg atoms and has attracted a tremendous amount of attention. The mechanism of the Rydberg dressing is to use the laser field coupling atomic ground state and the Rydberg state. The detune is large so that in the system mainly constituted by ground state atoms, a small amount of atoms of the Rydberg state was generated and also a frequency shift, forming a Rydberg-dressed state (accurately, is the superposition of the ground state and Rydberg state). In particular, the interactions between the Rydberg-dressed atoms show the intrinsic long-range and light-field manipulated features, which play a key role in the generation of spin squeezing (a macroscopic correlated system) for attaining precision resolution beyond the standard quantum limit. Rydberg dressing is easily controlled and no extra optical cavity is needed, comparing with other spin squeezing creation methods. Hence, we will focus on the ultra-cold Rydberg atomic gases (rubidium 87), and explore the key scientific and technical issues in the context of quantum precision measurement both experimentally and theoretically. We are going to improve the experimental platform of ultra-cold Rydberg atomic ensembles for quantum precision measurement, simultaneously developing novel theoretical and numerical methods. Moreover, the Rydberg-dressing mechanism and the consequent generation of a spin-squeezed macroscopic system will be intensively studied, and further applications in improving the stability of the atomic clocks are also investigated. Our explorations will provide powerful tools to improve the performances of atomic sensors including clocks, atom interferometers and atomic magnetometers and so on.