吾人計畫研究量子干涉效應對於激發原子在光子晶體中的輻射現象有何影響，吾人探討的原子形態為三階原子(包含V形、倒V形及階梯形三種) ，由於外加古典場的作用，使得原子的能態形成雙糾纏態，雙糾纏態的輻射將產生量子干涉，對於倒V形及階梯形原子此量子干涉產生破壞性干涉，此破壞性干涉可由輻射光譜中的暗線表現出來，至於V形原子則無此破壞性干涉；除了雙糾纏態輻射產生之量子干涉外，光子晶體本身為同調性儲庫，來至光子晶體能帶的輻射場可產生光場干涉效應，此光場干涉效應的大小取決於原子在光子晶體中的位置，原子在光子晶體中的輻射光譜將受此光場干涉效應作用，使得光譜中的共振頻率與原子在光子晶體中的位置變成有關，利用此光子晶體本身為同調性儲庫的模型，吾人可探討量子干涉效應如何影響激發原子在光子晶體中的輻射，外加古典場的強度、原子的形態及起始條件、原子在光子晶體中的位置及光子晶體能隙大小均將影響激發原子在光子晶體中的輻射光譜。
In this research project we would like to explore the effects of quantum interference on the spontaneous emission (SE) of the atom in photonic crystals (PCs) when either the excited or the ground state is split into Autler-Townes doublets by the action of an external driving field. There also exists quantum interference from the coherent photonic-band-gap reservoirs. This interference effect depends on the embedded position of the atom and the band-gap width. In this case quantum interference can be responsible for the appearance of unexpected SE phenomena. We propose study of quantum interference on spontaneous emission from a three level Ξ-type atom (the first-year proposal), Λ-type atom (the second-year proposal) and V-type (the third-year proposal) with one of two transitions coupled to the photonic crystal reservoirs. The SE spectrum of Ξ-type and Λ-type atoms in PCs is affected by quantum interference of Autler-Towns doublets and coherent reservoirs. Quantum interference between two competing decay amplitudes produces two dark lines in the emission spectrum. However physical mechanisms of the SE from a V-type atom are different from that of Ξ-type and Λ-type atoms. In a V-type atom, however, one can ascertain which of the two paths the atom has chosen to decay. Then, quantum interference from doublets is destroyed, and no dark lines are observed. Concluding from this series study of the SE spectrum we can find conditions of enhancing or suppressing SE of excited atoms by applying driving laser field. It depends on the embedding position of atom in PCs.
