Observation of the Influence of Generalized Parity on the Alignment Spectra in the Periodically Modulated Warm Atomic Ensemble.

Periodically modulated systems with parity symmetry have been extensively investigated in recent years and exhibited various novel phenomena and potential applications in quantum technologies. In this study, a pump‐probe structure is used to observe the influence of generalized parity on the alignment spectra of magnetic resonance in a periodically biharmonic modulated warm atomic cesium ensemble. The alignment spectra are symmetric when the generalized parity of modulated Floquet atomic ensemble is present. The breaking of spectral symmetry is accompanied by the absence of generalized parity. The influence of generalized parity on atomic alignment polarization distribution is analyzed based on the perspective of the angular‐momentum probability surface. A necessary and sufficient condition for generalized parity to maintain spectral symmetry is verified experimentally and theoretically, providing a new perspective to investigative complex periodic modulation system. The results are universally applicable to atomic and solid‐state systems. [ABSTRACT FROM AUTHOR]