D_2^+强场解离的电子局域化随激光波长的非线性变化

Non linear wavelength dependence of electron localization in strong-field dissociation of D_2^+

研究了周期量级激光脉冲的波长变化对氘分子离子D_2^+强场解离过程中电子局域化的影响.通过求解波恩,奥本海默近似下关于核波包演化的双能级含时薛定谔方程,发现电子局域化的不对称性对激光波长有反常的依赖关系.电子局域程度随着波长的增加呈现增强的趋势,但在某些波长范围内电子局域化出现了显著的衰减.导致电子局域化程度被削弱的直接原因是在某些波长下不同振动态的电子局域化对脉冲载波包络相位的响应出现了反相抵消.分析表明,当波长发生变化时,决定电子局域化的核运动和电子运动在外场作用下出现不一致的运动响应,最终导致了电子局域化的非线性变化.

The wavelength dependence of the electron localization in dissociating molecular ion D2^＋ is investigated via solving the time-dependent Schr？dinger equation of the two-state model of the molecular ion. Our results reveal an anomalous dependence of the electron localization on the laser wavelength. Overall, the degree of the electron localization shows a growing trend with the increase of wavelength, but it drops off obviously at some wavelengths. It is found that the localization asymmetries for some vibrational states become opposite in phase when the wavelength is changed, leading to the decline of the electron localization. Further analysis shows that the nuclear and electronic motions that determine the electron localization respond inconsistently to the variation of the wavelength, ultimately resulting in the non-linear dependence of the electron localization on the laser wavelength.