Quantum control study of multilevel effect on ultrafast isotope-selective vibrational excitations

超高速同位体選択的振動励起における多準位効果についての量子制御研究

黒崎 譲; 横山 啓一  ; 横山 淳

Kurosaki, Yuzuru; Yokoyama, Keiichi; Yokoyama, Atsushi

Quantum optimal control calculations have been carried out for isotope-selective vibrational excitations of the cesium iodide (CsI) molecule. Considering a gaseous isotopic mixture of CsI and CsI, the initial state is set to the condition that both CsI and CsI are in the vibrational ground level ( = 0) and the target state is that CsI is in the = 0 level while CsI in the first-excited level ( = 1). We find, using the density-matrix formalism, that perfect isotope-selective excitations for multilevel systems including more than ten lowest vibrational states can be completed in much shorter time scales than those for two-level systems. This multilevel effect comes from the large isotope shifts of the vibrational levels of 1. To check the reliability of the calculation we also employ the conventional wave-packet formalism and obtain almost the same results as those with the density-matrix formalism.