Open quantum dynamics of a three-dimensional rotor calculated using a rotationally invariant system-bath Hamiltonian: Linear and two-dimensional rotational spectra.
Open quantum dynamics of a three-dimensional rotor calculated using a rotationally invariant system-bath Hamiltonian: Linear and two-dimensional rotational spectra.
复制标题
使用旋转不变系统浴哈密顿量计算的三维转子的开放量子动力学：线性和二维旋转谱。
DOI：
10.1063/1.5108609
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Y. Tanimura
中科院分区：
文献类型：
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作者：
Yuki Iwamoto;Y. Tanimura
我们考虑了一个三维空间的旋转不变系统浴（RISB）模型，该模型由一个线性刚性转子通过转子欧拉角函数独立耦合到三个谐振子浴来描述。虽然该模型已被开发用于研究溶剂中偶极分子的介电弛豫作为经典德拜弛豫问题，但在这里我们将其作为开放量子动力学问题进行研究。具体地说，这里提出的治疗是作为先前工作的延伸[Y。Iwamoto和Y. tananimura， J. Chem。物理学报149,084110(2018)]，其中我们研究了二维（2D） RISB模型，到三维（3D） RISB模型。与二维情况一样，由于总哈密顿量的能量离散化不同，三维RISB模型所描述的动力学与旋转Caldeira-Leggett模型所描述的动力学有很大不同。为了说明由角动量和磁量子数描述的量子三维转子系统的特征，我们推导了高温情况下三维RISB模型的量子主方程（QME）和层次运动方程。利用QME，我们分别计算了由转子偶极子的线性响应函数和非线性响应函数定义的线性和二维旋转谱。在二维旋转光谱中可以清楚地观察到由极化Stark场引起的角动量态和磁态之间的量子跃迁以及系统浴相互作用。
We consider a rotationally invariant system-bath (RISB) model in three-dimensional space that is described by a linear rigid rotor independently coupled to three harmonic-oscillator baths through functions of the rotor's Euler angles. While this model has been developed to study the dielectric relaxation of a dipolar molecule in solvation as a problem of classical Debye relaxation, here we investigate it as a problem of open quantum dynamics. Specifically, the treatment presented here is carried out as an extension of a previous work [Y. Iwamoto and Y. Tanimura, J. Chem. Phys 149, 084110 (2018)], in which we studied a two-dimensional (2D) RISB model, to a three-dimensional (3D) RISB model. As in the 2D case, due to a difference in the energy discretization of the total Hamiltonian, the dynamics described by the 3D RISB model differ significantly from those described by the rotational Caldeira-Leggett model. To illustrate the characteristic features of the quantum 3D rotor system described by angular momentum and magnetic quantum numbers, we derive a quantum master equation (QME) and hierarchical equations of motion for the 3D RISB model in the high-temperature case. Using the QME, we compute linear and 2D rotational spectra defined by the linear and nonlinear response functions of the rotor dipole, respectively. The quantum transitions between the angular momentum states and magnetic states arising from polarized Stark fields as well as the system-bath interactions can be clearly observed in 2D rotational spectroscopy.