Physics Department, Zhejiang University, 38 ZheDa Road, Hangzhou, Zhejiang 310027, China.
J Chem Phys. 2018 Jun 21;148(23):234107. doi: 10.1063/1.5028306.
In the framework of the quantum-classical Liouville equation (QCLE), the quantum kinetic expansion (QKE) of the spin-boson model is extended to an arbitrary combination of the bath potential and the system-bath interaction. The mixed quantum-classical estimation of the QKE rate kernels and modification functions are transformed into averages of deterministic classical trajectories over the Wigner initial distribution. For the standard spin-boson model, the QCLE-QKE method produces exactly the same result as that from full quantum dynamics and the numerical applicability of the approximate action-angle initial distribution is verified. For an anharmonic bath with the quartic potential, the QCLE-QKE calculation under the action-angle initial distribution illustrates the influence of this specific anharmonicity. With the increase of the quartic parameter, the fourth order QKE corrections are suppressed and the short-time population transfer is accelerated together with an enhanced quantum oscillation.
在量子-经典李雅普诺夫方程 (QCLE) 的框架内，将自旋-玻色子模型的量子动力学展开(QKE)扩展到任意的浴电势和系统-浴相互作用的组合。QKE 速率核和修正函数的混合量子-经典估计被转化为在维格纳初始分布上对确定性经典轨迹的平均值。对于标准的自旋-玻色子模型，QCLE-QKE 方法产生的结果与完全量子动力学完全相同，并且验证了近似作用-角度初始分布的数值适用性。对于具有四次方势的非谐浴，在作用-角度初始分布下的 QCLE-QKE 计算说明了这种特定非谐性的影响。随着四次方参数的增加，第四阶 QKE 修正被抑制，短时间的种群转移被加速，同时伴随着增强的量子振荡。
