Theoretical study of detection and control of quantum coherence using a multi-dimensional spectrum

我们从理论上研究了量子相干性在耗散环境中的作用。该方程组以非微扰的方式处理浴，并考虑到噪声的非马尔可夫关联时间，适用于低温系统。此外，这种形式允许我们同时处理经典极限和隧穿区，并且有助于识别纯量子力学效应。利用Caldeira-Leggett哈密顿量，我们严格计算了由周期势模型描述的棘轮系统的量子耗散动力学和共振隧穿问题。然后，我们扩展了减少层次运动方程的方法，包括过阻尼和欠阻尼德鲁德研究电子转移过程。非马尔可夫性也从这个方法进行了研究。非线性响应函数也被用来分析量子相干性的作用。

We theoretically investigate a role of quantum coherence under a dissipative environment by means of the reduced hierarchy equations of motion approach. The set of equations treats the bath in a nonperturbative manner and is applicable to a low-temperature system with taking into account the non-Markovian correlation time of noise. In addition, this formalism allows us to treat both the classical limit and the tunneling regimes, and it is helpful for identifying purely quantum mechanical effects. By employing the Caldeira-Leggett Hamiltonian, we rigorously calculated the quantum dissipative dynamics of a ratchet system described by a periodic potential model and resonant tunneling problems. We then extended the reduced hierarchy equations of motion approach to include both overdamped and underdamped Drude to study electron transfer processes. Non-Markovianity was also studied from this approach. Nonlinear response functions were also utilized to analyze a role of quantum coherence.