Super low-frequency electric field measurement based on Rydberg atoms

Abstract

We demonstrate the measurement of super low-frequency electric field using Rydberg atoms in an atomic vapor cell with inside parallel electrodes, thus overcoming the low-frequency electric-field-screening effect at frequencies below a few kHz. Rydberg electromagnetically induced transparency (EIT) spectra involving 52D5/2 state is employed to measure the signal electric field. An auxiliary DC field is applied to improve the sensitivity. A DC Stark map is demonstrated, where the utilized 52D5/2 exhibits m j = 1/2, 3/2, 5/2 Stark shifts and splittings. The m j = 1/2 state is employed to detect the signal field because of its larger polarizability than that of m j = 3/2, 5/2. Also, we show that the strength of the spectrum is dependent on the angle between the laser polarizations and the electric field. With optimization of the applied DC field to shift the m j = 1/2 Rydberg energy level to a high sensitivity region and the laser polarizations to obtain the maximum m j = 1/2 signal, we achieve the detection of the signal electric field with a frequency of 100 Hz down to 214.8 µV/cm with a sensitivity of 67.9 µV cm−1Hz−1/2, and the linear dynamic range is over 37 dB. Our work extends the measurement frequency of Rydberg sensors to super low frequency with high sensitivity, which has the advantages of high sensitivity and miniaturization for receiving super low frequency.

Theoretical study on Stark effect of Rydberg atom in super low frequency electric field measurement

“…According to the quadratic Stark theory, Rydberg atoms exhibit the following relationship with an external electric field [29].…”

Measurement of low-frequency electric field waveform by Rydberg atom-based sensor

“…2020年, Bai等 [24] 基于冷原子系统, 通过单光子激发制备 特定轨道角动量里德伯态, 实现低频和直流电场测 量, 对应的场强为4.9 mV/cm. 2022年, 杜艺杰等 [25] 基于里德伯原子天线实现了MHz -GHz频段的电 磁场测量. 2023年, Li等 [26] 利用原子气室内部平行 电极实现低频电场测量, 频率为100 Hz时的典型 场强值为214.8 μV/cm, 线性动态范围超过37 dB.…”

Low-frequency weak electric field measurement based on Rydberg atoms using cavity-enhanced three photon system

“…One possible solution to the shielding problem is to place an electrode plate inside the vapor cell [15][16][17][18][19] and apply a voltage to generate an electric field. However, this method is only suitable for laboratory research and is not practical for measuring electric fields in practical application scenarios.…”