Control of Molecular Quantum State Character by Coherence Effects

相干效应控制分子量子态特征

• 批准号: 1205903
• 负责人: A. Marjatta Lyyra
• 金额: $ 40.5万
• 依托单位: Temple University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1205903&HistoricalAwards=false
• 关键词: Control; Molecular; Quantum; State; Character

Marjatta Lyyra's research group at Temple University is supported by the Atomic, Molecular and Optical Physics Program to carry out a series of fundamental studies of the interaction of light with small molecules in the frequency domain. Her group has developed applications of quantum optics for molecular systems including electromagnetically induced transparency and the Autler-Townes (AT) effect. These studies have facilitated a shift of quantum optics studies to molecular systems with practical applications as the goal. The complex molecular energy level structure, molecular interactions, and relaxation pathways provide a rich testing ground of coherence effects for controlling molecular dynamics and quantum state character. Through combined experimental and theoretical studies her research group has demonstrated control of molecular angular momentum alignment, for example. Another important application of the Autler-Townes effect is its use as a precision probe of the internuclear distance-dependent transition dipole moment functions, which are at the heart of the interaction of light with molecules. These measurements rely on the measurement of the Autler-Townes splitting from the lineshape of the control laser transition combined with an accurate measurement of the electric field amplitude of this laser. Another application of the AT effect involves external optical control over the mixing between a pair of closely-spaced molecular singlet and triplet eigenstates that are weakly perturbed by the spin-orbit interaction. The AT effect causes the nominal singlet level to split into a pair of field modified levels, one of which tunes closer to the triplet, resulting in increased singlet-triplet mixing, and the other farther from the triplet, resulting in decreased singlet-triplet mixing. Thus this optical control mechanism can be used to "tune" the spin-orbit mixing coefficients and as a result control quantum state singlet and triplet character.In addition to developing new applications of quantum interference and coherence effects, this research bridges traditionally separate research communities: molecular spectroscopy and dynamics on one hand, and quantum optics and control on the other hand. Due to the fundamental nature of this research the results are broadly applicable. Examples include finding optimal excitation pathways for ultracold molecule formation and role of valence electron spin polarization in photochemistry.In this project, young scientists, many of whom are women, participate in forefront scientific research at the undergraduate, graduate and postdoctoral levels and as a result develop critical experience and confidence for their future participation in the scientific and technical workforce.

Marjatta Lyyra在坦普尔大学的研究小组得到了原子，分子和光学物理计划的支持，在频域中对光与小分子相互作用进行了一系列基础研究。她的团队开发了量子光学在分子系统中的应用，包括电磁诱导透明和Autler-Townes（AT）效应。 这些研究促进了量子光学研究向以实际应用为目标的分子系统的转移。复杂的分子能级结构、分子间相互作用和弛豫路径为控制分子动力学和量子态特性提供了丰富的相干效应测试基础。通过结合实验和理论研究，她的研究小组已经证明了分子角动量排列的控制。奥特勒-汤斯效应的另一个重要应用是它作为核间距离依赖跃迁偶极矩函数的精确探针，这是光与分子相互作用的核心。这些测量依赖于从控制激光跃迁的线形测量Autler-Townes分裂，并结合该激光的电场振幅的精确测量。AT效应的另一个应用涉及对一对紧密间隔的分子单重态和三重态本征态之间的混合的外部光学控制，这些本征态被自旋轨道相互作用弱扰动。AT效应导致标称单重态能级分裂成一对场修改能级，其中一个更接近三重态，导致增加的单重态-三重态混合，另一个更远离三重态，导致减少的单重态-三重态混合。因此，这种光学控制机制可以用来“调谐”的自旋轨道混合系数，从而控制量子态的单线态和三线态的字符。除了开发量子干涉和相干效应的新应用，这项研究桥梁传统上分离的研究社区：一方面分子光谱学和动力学，另一方面量子光学和控制。由于这项研究的基本性质，其结果具有广泛的适用性。例子包括寻找超冷分子形成的最佳激发途径和价电子自旋极化在光化学中的作用。在这个项目中，青年科学家，其中许多是妇女，参加本科生、研究生和博士后一级的前沿科学研究，从而为他们将来参加科学和技术工作积累了重要的经验和信心。