Physical Review A
Effect of energy shifts on the spontaneous emission modification via quantum interference
Shuai Yang, Jun Xu, Shi‐Yao Zhu, Muhammad Suhail Zubairy
Abstract
Quantum interference in spontaneous emission from a four-level atom is investigated with the counter-rotating terms and the energy shifts included. The atom has two upper levels which are coupled to a common lower level by the same vacuum modes and are driven by a coherent field to an auxiliary level. The effect of the counter-rotating terms in the coupling through the vacuum modes is taken into account by a unitary transformation method. We show how the quantum interference due to the energy shifts affects the spontaneous emission.