发表机构
Ecole Polytechnique Fédérale de Lausanne (EPFL)（洛桑联邦理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究提出基于经典相空间动力学的非微扰框架，可处理任意时变电场下分子振动激发问题，适用于强弱场，为超快光谱非微扰态制备提供支撑。
AI 中文摘要
我们提出了一种非微扰框架，用于处理任意时变电场驱动下分子系统振动激发的量子问题。对于具有线性偶极耦合的简谐势，电场诱导的动力学可由位移相干态精确描述，其演化完全由复相空间坐标决定。该坐标的闭式表达式清晰区分了共振与非共振区域。无论共振还是非共振驱动，所得振动布居均遵循由无量纲时变相空间位移决定的泊松分布。共振驱动会导致相空间位移增大，而驱动频率与振动频率间的有限失谐会使相空间位移及振动激发呈指数级抑制。该方法在弱场极限下可退化为标准含时微扰理论，且在微扰处理失效的强场区域仍有效。我们的结果为振动控制提供了清晰的相空间图像，并为超快光谱中的非微扰态制备提供了可能。
英文摘要
We present a non-perturbative framework for the quantum treatment of vibrational excitation in molecular systems driven by electric fields with arbitrary time dependence. For harmonic potentials with linear dipole coupling, the field-induced dynamics is exactly described by a displaced coherent state, whose evolution is completely determined by a complex phase-space coordinate. Closed-form expressions for this coordinate reveal a clear distinction between resonant and non-resonant regimes. The resulting vibrational populations follow a Poisson distribution determined by a dimensionless time-dependent phase-space displacement, for both resonant and non-resonant driving. Resonant driving results in an enhanced phase-space displacement, whereas finite detuning between the driving and vibrational frequencies leads to an exponential suppression of the phase-space displacement and vibrational excitation. While the approach reduces to the standard time-dependent perturbation theory in the weak-field limit, it remains valid in the strong-field regime, where perturbative treatments fail. Our results provide a transparent phase-space picture of vibrational control and enable non-perturbative state preparation in ultrafast spectroscopy.
