We regard a vibronic system where laser-excitation coherently couples two electronic states. The interaction with an environment, leading to vibrational relaxation, is treated within the quantum-state diffusion method. Two propagation schemes are compared which involve stochastically correlated dynamics in the two states on the one hand and uncorrelated dynamics on the other. Whereas expectation values of various observables are found to be insensitive to the propagation scheme, phase-sensitive quantities are not. This is illustrated regarding third-order time-dependent polarizations and two-dimensional vibronic spectra derived from them.

中文翻译：

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不同电子状态下的随机相关和不相关的量子态扩散动力学：三阶极化和二维电子振动谱

我们认为一个振动系统，其中激光激发相干耦合两个电子状态。在量子态扩散方法中处理了与环境的相互作用，从而导致振动弛豫。比较了两种传播方案，一方面涉及两种状态下的随机相关动力学，另一方面涉及不相关的动力学。尽管发现各种可观测值的期望值对传播方案不敏感，但对相位敏感的量却不敏感。这是关于三阶随时间变化的极化和从中导出的二维振动光谱的说明。