Research Groups

Atomic Ensemble Precision Measurement Group

Quantum Precision Measurement

About

Atomic Ensemble Precision Measurement Group was established in October 2019 and is led by Prof. Renfu Yang. The team focuses on the research of quantum sensing technology and uses a thermal atomic ensemble as the sensing unit to research quantum precision measurement technology of physical quantities such as time-frequency, magnetic field, and electric field. They are committed to developing with reliability and small SWaP-C (Size, Weight, Power, and Cost), focusing on the miniature CPT atomic clocks, Rydberg atomic antenna, atomic magnetometer, diamond NV center, etc. There are 15 team members, including 7 scientific researchers, 3 senior engineers, 1 postdoctoral fellow, 3 PhD candidates, and 1 scientific research assistant. The team now is undertaking two major scientific funds. The main research directions and progress are as follows:

● Miniature atomic clock

The atomic clock is based on Coherent Population Trapping (CPT) technology. The current CPT atomic clock is developed with a volume of 15 cm³, weighs 38 g, power consumption < 1 W, frequency stability is < 3E-11@1s, < 1E-11@10s, < 3E-12@100s, phase noise is better than -140 dBc@10kHz, and the frequency accuracy after calibration is better than 4E-12. The onboard tests of the miniature atomic clocks based on a four-propeller drone have been carried out. The overall technical indicators are better than similar products of relevant international companies.

Fig. 1 Prototype of the miniature atomic clock

● Rydberg atomic antenna

The research focuses on sensing and monitoring of broadband and highly sensitive electric-field based on room-temperature Rydberg atoms. A programmable narrow linewidth fiber laser has been developed to realize the automatic locking and control, and the compact Rydberg atomic measurement module has been successfully developed. A reception experiment of high-definition video (the resolution of 720P) using the Rydberg atomic antenna is realized.

Fig. 2 Compact system of the Rydberg atomic antenna

● Diamond NV center

  A scanning confocal microscope has been developed for solid-state quantum studies, the system can be used for manipulation and readout of the electron spins of solid-state quantum platforms such as NV centers in diamond, SiV centers in silicon carbide and so on. Using this system, high-spatial-resolution imaging and property characterization of some novel materials at ambient and high-pressure conditions can be performed. The NV diamond samples in nanoscale size and high-density NV ensemble in bulk diamond have been prepared by electron beam irradiation, and NV ensemble also have been successfully grown in bulk diamond by CVD method.

Fig. 3 The scanning confocal microscope based on diamond NV center

● Atomic magnetometers

  Based on the non-magnetic VCSEL laser aiming to reduce the magnetic-noise of light source, a small Bell-Bloom magnetometer prototype is developed with a measurement sensitivity better than 200 fT/√Hz. A magnetic field gradient measurement system is also built with a volume of the integrated gradient probe less than 20 cm³.

Fig. 4 Experimental system for measurement of atomic magnetic field

 

 

Publication lists:

(1) F.M. Stürner, Y. Liu, P.-O. Colard, M. Markham, and F. Jelezko, Magnetometry based on the excited-state lifetimes of a single nitrogen-vacancy center in diamond, Appl. Phys. Lett. 119(13), 134001 (2021).

(2) Baha Sakar, Yan Liu, Sibylle Sievers, Volker Neu, Johannes Lang, Christian Osterkamp, Matthew L. Markham, Osman ?ztürk, Fedor Jelezko, and Hans W. Schumacher, Quantum calibrated magnetic force microscopy, Phys. Rev. B 104(21), 214427 (2021).

(3) Wenhao Luo, Hong Zhang, Yan Liu, Xiaogang Wei, Yanhua Wang, Renfu Yang, A dual-axis high-order harmonic and single-axis phase-insensitive demodulation atomic magnetometer for in situ NMR detection of Xe, J. Appl. Phys. 132, 144401 (2022).

(4) Yijie Du, Nan Cong, Xiaogang Wei, Xiaonan Zhang, Wenhao Luo, Jun He, and Renfu Yang, Realization of multiband communications using different Rydberg final states, AIP Advances 12, 065118 (2022).

(5) Weina Liu, Md Noor A. Alam, Yan Liu, Viatcheslav N. Agafonov, Haoyuan Qi, Kaloian Koynov, Valery A. Davydov, Rustem Uzbekov, Ute Kaiser, Theo Lasser, Fedor Jelezko, Anna Ermakova, and Tanja Weil, Silicon-Vacancy Nanodiamonds as High Performance Near-Infrared Emitters for Live-Cell Dual-Color Imaging and Thermometry, Nano Lett. 22(7), 2881–2888 (2022).

 (6) 杜艺杰, 丛楠, 何军, 杨仁福，基于室温里德堡原子天线的宽频带电场测量, 导航与控制, 21, 192, (2022).

(7) Rong Wang, Yongxiong Chen, Xiaonan Yan, Nan Cong, Delei Fang, Peipei Zhang, Xiubing Liang, and Wenwang Wu. Experimental Investigations on the Mechanical Performances of Auxetic Metal-Ceramic Hybrid Lattice under Quasi-Static Compression and Dynamic Ballistic Loading. Appl. Sci., 13, 7564 (2023).

(8) 董先启, 刘岩, 杨仁福，基于金刚石氮-空位色心的温度测量技术，宇航计测技术, 43, 3 (2023).

Group Leader: Renfu Yang

Research Directions:

●  CPT atomic clocks and Micro-PNT

●  Atomic electrometers and measurements of electric field

●  Atomic magnetometers and measurements of magnetic field

●  Solid-state quantum sensors and diamond NV center