空场诱导相干性对倒转Y-型四能级原子系统中单光子和双光子吸收性质的影响

Effects of vacuum-induced coherence on single-and two-photon absorption in a four-level inverted Y-type atomic system

当倒转Y-型四能级原子的两基态能级邻近简并时,连接基态的两个跃迁路径与同一个真空辐射场相互作用便导致了空场诱导相干性.空场诱导相干性能使该原子在探测光共振点处的单光子和双光子电磁诱导透明现象减弱,而在其它失谐量处会导致单光子增益现象.同时,外加相干光场的相对相位对原子的吸收性质也有重要影响.

When the transitions connected by two nearly degenerate ground levels with an intermediate level in a four-level inverted Y-type atom interact with the same vacuum radiation field, which will lead to the quantum interference and create the vacuum-induced coherence. We find that the vacuum-induced coherence can suppress the single-and two-photon transparency at resonance and lead to single-photon probe gain at other frequency. Meanwhile, it is shown that the single-and two-photon absorption spectra can be drastically modulated by the relative phase between the probe and coupling fields.