New progress in detection of atomic magnetic resonance by laser

Editor's Note

Recently, the research group led by Professor Li and Professor Huang from the School of Physical Science and Technology has made new progress in the study of periodically driven laser pump—detection of cesium atoms based on tensor polarization. Relevant paper Observation of the Influence of Generalized Parity on the Alignment Spectra in the Periodically Modulated Warm Atomic Ensemble was published in Laser & Photonics Reviews, a leading international journal of optics. The first author of this paper is Geng Xuxing, a doctoral student of our university, and the co-corresponding authors are Li Gaoxiang and Huang Guangming. Associate Professor Yang Guoqing of Hangzhou Dianzi University, Professor Wu Shaoping from the School of Physical Science and Technology of our university, and doctoral student Jin Kai and Tang Wangwang are the co-authors.

(a) Schematic of the experimental setup. 

(b)When the generalized parity is present, the alignment spectra are symmetric.

(c) When the generalized parity is absent, the alignment spectra are asymmetric.

Floquet system with dynamical parity symmetry has many novel physical phenomena such as symmetry-protected selection rules, the Floquet lattice, Floquet topological insulator and so on.

Based on these phenomena, the Floquet maser, Floquet spin locking technique and other related technologies have attracted extensive attention. At present, the research about dynamical symmetry mainly focuses on periodically modulated magnetic dipole moment of a spin 1/2 particle, while the high order polarized magnetic moments of multilevel systems has never been addressed before. Floquet modulated high order polarization moments and the related high-order coherence in multi-level systems play an important role in applications such as dimension expansion and optical nonlinearity enhancement of quantum systems. Thus, the research of generalized parity of high order polarization moments is now at the forefront with great significance.

To solve this problem, this research team put forward the generalized parity theory of high order polarization moments for Floquet-modulated multilevel warm atomic magnetic resonance system with angular momentum J (J>1) and studied the properties of tensor polarization (alignment) with generalized parity. At last, they revealed the physical law of spectral symmetry of high order polarization moments protected by generalized parity. On this basis, they designed and carried out the experiment of periodically driving laser pump—probe cesium atomic magnetic resonance and verified generalized parity protect tensor polarized spectral symmetry theory (As shown by figure 1). The relevant research results not only enrich the generalized parity theory and experiment of Floquet driven high order polarization moments of multilevel quantum systems, but also benefit the design of vector atomic magnetometer with high sensitivity based on high order polarization moments.

The research was supported by a grant from the National Natural Science Foundation of China.

Links to the related paper: https://doi.org/10.1002/lpor.202100614

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Editor: Marisa(trainee)

Reviser:Jerry(trainee)

Designer:Jessica(trainee)