四能级系统中相位控制电磁诱导透明研究

提出了一种利用微波场的相对相位调控电磁诱导透明(EIT)光谱特性的方法. 在外加双微波驱动场的准Λ型四能级原子系统中,通过求解系统的密度矩阵方程得到探测场的吸收谱,分析了电磁诱导透明窗口的位置随微波驱动场相位的变化规律,并借助缀饰态理论给出了准确解释. 结果表明,对于确定的作用场强度,调节微波驱动场的相位可实现电磁诱导透明的频率位置及间隔的准确控制. 关键词： 四能级原子系统 电磁诱导透明(EIT) 相位控制 微波场

Phase-dependent electromagnetically induced transparency in a four-level atom system

We present a method to control the electromagnetically induced transparency (EIT) in a four-level system with a coupling field, a weak probe field and two microwave driven fields. By sloving the density matrix equations, the numerious result is obtained. It is shown that the EIT resonance can be split into doublets and the spectral position of EIT window is determined by the relative phase between two microwave fields for fixed intensity of the microwave field. Therefore, the microwave field can be used to open more than one EIT window and by controlling their phase difference we can perform EIT frequency tuning. The structure in the spectrum can be explained using the dressed-state formalism.