Characterization of Fine Structures in Electronic States by Raman Heterodyne Detection Using Optical Transition.

在掺有LaF_3的Pr^<3+>周围的^<139> La原子核在1.5 K下，在Pr^<3+>^3H_4-^3P_0跃迁（20925 cm^<-1>）上，以光学射频诱导的相干拉曼拍下发生了四极跃迁。由于激发^3P_0状态下的有效^<141>Pr核磁矩小于基态，Pr^<3+>光激发下Pr-La相互作用减小，使得La四极跃迁与Pr光跃迁耦合。观察到四个磁性不相等的La原子核，揭示了杂质Pr^<3+ b>离子周围La原子的不同局域环境。

The quadrupole transitions of ^<139> La nuclei around Pr^<3+> doped in LaF_3 have been detected as an optical-rf induced coherent Raman beat on the Pr^<3+>^3H_4-^3P_0 transition (20925 cm^<-1>) at 1.5 K.Because the effective ^<141>Pr nuclear magnetic moment is smaller in the excited ^3P_0 state than in the ground state, the Pr-La interaction decreases upon Pr^<3+> optical excitation, which makes the La quadrupole transitions couple with the Pr optical transition. Four magnetically inequivalent La nuclei were observed, revealing different local environments of La atoms around impurity Pr^<3+> ions.