双窗口电磁诱导透明的相干瞬态研究

Coherent transient investigation in electromagnetically induced transparency with double windows

通过求解准A-型四能级系统的含时密度矩阵方程,研究了系统从单窗口电磁诱导透明(EIT)向双窗口EIT转换的相干瞬态过程。该过程表现为一种量子拍频形式,并利用缀饰态理论很好地解释了量子拍频的规律,指出这种量子拍频效应源于射频驱动场所引起劈裂能级间的量子相干。结果表明:当探测场与相应的裸态跃迁能级共振作用时,拍频频率等于射频驱动场Rabi频率的二分之一;当探测场与强射频驱动场和原子系统相互作用所产生的缀饰态跃迁能级共振时,拍频频率等于射频驱动场的Rabi频率。

A theoretical study of the time-dependent probe response of a single electromagnetically induced transparency （EIT） window to double EIT windows is presented by numerically solving the equations of motion of the density matrix in a quasi-A-four-level configuration. There is a coherent transient process with high quantum beats. This effect can be explained using the dressed state formalism. The quantum beats result from quantum coherence effect between the levels driven by RF field. The results show that when the probe field is on resonance with a＇ bare-State transition, the beat frequency is one-half of RF Rabi frequency in transient absorption response. While the probe field is on resonance with a dressed-state transition, which results from the atom system interaction with strong RF field, the beat frequency equals the RF Rabi frequency in transient absorption response.