Quantum microwave electric field measurement technology based on enhancement electric filed resonator
Bo Wu, Yi Lin, Feng-Chuan Wu, X. Q. Chen, Qiang An, Yi Liu, Yunqi Fu
Abstract
Rydberg atoms based quantum microwave measurement technology has significant advantages such as self-calibration, traceability, high sensitivity and stable uniformity of measurement. In this work, from the dimension of traditional electromagnetic theory, an electric field local enhancement technique for quantum microwave measurements is developed to improve the sensitivity of quantum microwave receiver. The theoretical basis of this method comes from the different mechanisms of realization of microwave reception in quantum microwave receivers and classical receiver. Classic receivers use antennas to collect microwave energy in space to signal reception; quantum microwave receivers measure the strength of the electric field in the path of a laser beam in an atomic gas chamber (the beam is about 100 µm in diameter) to realize the signal reception. Therefore, the sensitivity of quantum microwave receiver can be improved by increasing the electric field strength in the path of laser beam. The critical physical mechanism is the multi-beam interference at the open end and the short-circuited end of the structure. The results show that with the decrease of gap height of parallel plates, the enhancement factor of electric field strength increases rapidly and the power density compression capability is greatly improved. The |69D<sub>5/2</sub><inline-formula><tex-math id="Z-20230113213135">\begin{document}$\rangle $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="3-20221582_Z-20230113213135.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="3-20221582_Z-20230113213135.png"/></alternatives></inline-formula> experiments verify that the structure can achieve a 25 dB electric field enhancement at 2.1 GHz. This research is expected to be helpful in improving the sensitivity of measurement based on atomic measurement capabilities and in promoting the practical development of quantum microwave measurement technology.