基于冷里德堡原子的微波电场精密测量研究

Atomic spectroscopy is the basis for many precise measurements of physical quantities, such as length, time, magnetic field as well as some physical constants, while construction of a robust interferometer is also a focus topic in precise measurements. The plan of this project is follows: 1) we intend to realize a microwave electrometry with clod Rydberg atoms. The method can be used to measure the electric field strengths over a wide range of frequencies: 1 GHz to 500 GHz. 2) we plan to develop some geometric controls with fault-tolerant feature. All or part of the phases in the interferometer are pure geometric phases, thus the interferometer is immune to certain noises. Essentially the.manipulation can be a super-adiabatic operation based on geometric phase. 3) The geometric interferometer developed in 2) will be further used in the microwave electrometry with Rydberg atoms. The sensitivity is expected to be improved by 1-2 orders. The accurate measurement of microwave electric fields is important for a host of applications, such as the experimental high-resolution weather radar and satellite communications. The fault-tolerant geometric interferometer we developed can also be used in many precise measurements. All contents we intended to investigated are included in the main object of the project “Physics in Precise Measurements".

冷原子已经逐步成为时间、空间、物理常数和磁场等众多物理量精密测量的主要载体。本项目拟研究的主要内容是：1）将结合原子激光冷却技术和新兴的量子操控技术，开展基于冷里德堡原子的微波电场强度的精密测量研究，将电场强度测量转化为谱线测量，实现1到500GHz微波电场连续频点的精密测量。2）发展基于有内禀容错特性的几何相位操控方法，理论提出和实验实现具有对噪声鲁棒性高，干涉对比度高的超绝热几何干涉仪。3）利用超绝热几何干涉仪提高干涉条纹对比度，并把微波电场测量转化为干涉仪相位测量，进一步提高微波电场测量精度。预计微波电场强度的测量能比目前国际上的8微伏/ 厘米高1-2个量级。微波电场的精密测量可对微波在民用、科学研究、国防安全等方面的需求提供关键技术基础；超绝热几何干涉仪的研制将为精密测量过程中抑制噪声提供新机理。这些研究内容都属于“精密测量物理”重大研究计划指南中的核心科学问题。

在原子微波天线和几何/拓扑量的应用及其测量方面取得了创新成果。提出并实现了基于冷原子电磁诱导吸收来测量微波电场强度的方法，直接溯源至100uV/cm；并实验测得了0.41uV/cm的极小微波场强。提出了一种新的测量波函数的方法，并对光子的时域波函数进行了直接实验测量。合作开展了超导比特的几何相干控制，基于超导比特的精确操控实验实现了几何相位干涉，探测了几何相位积累后的拓扑陈数，并据此模拟了拓扑麦克斯韦准粒子；在超导比特中实验测量了量子度规，量子度规等价于Fisher信息的测量，并将实验结果推广到整个量子几何张量的测量。发表标注基金资助的论文27篇，其中 Physical Review Letters 6 篇，Nature Photonics 1 篇,Advances in Physics 1篇， Physical Review A/B 14 篇， Chinese Phys. Lett. 3 篇。