离子阱精密测量

Precision measurement with trapped ions

随着基于经典物理学的测量精度逐渐逼近上限,使用量子系统进行精密测量成为一个重要的研究领域.近年来,随着实验技术的快速发展和操控能力的大幅提升,囚禁在势阱中的离子系统在精密测量方向展示了极大的潜力.本文介绍了基于离子阱系统的光频原子钟、磁力计和陀螺仪的理论方案、实验进展和未来发展,重点关注离子阱系统与其他物理体系相比所具有的特点和优势,其在突破测量精度、提高稳定性以及促进设备小型化等方面的应用前景.

Measuring physical quantities with unprecedented precision is one of the most important paradigms to extend our fundamental understanding of nature. With the development of new quantum techniques, quantum systems have become a promising platform along the path to pursue higher accuracy and stability of measurement, while the classical methods are approaching their own limitation. Owing to its high stability, long coherence time and good controllability of quantum states, the trapped ion system has attracted much attention as a promising platform for quantum metrology. Recent progress on quantum control of trapped ions in both the scientific and technological aspects greatly advance the potential applications in precision measurement of various physical quantities. The invention of optical comb with ultra-stable laser brings us a new approach to develop a clock working on optical frequency, and features a much higher precision than microwave.This achievement has the potential reform the definition of the basic unit of the international system of units in the near future. New methods of dynamic decoupling or preparing special dressed states significantly extend the coherence time,such that an ultra-sensitive detection of magnetic field can be achieved. By introducing a spin-dependent kick in the phase space, one may also realize rotation measurement with trapped ions and obtain high accuracy with a chip-size apparatus. In this short review, we introduce the principles and designs of optical clock, magnetometer and gyroscope based on trapped ion systems. Owing to its unique features, this platform presents many advantages which can help improving sensitivity and stability, as well as building transportable devices.