论文标题
复杂的相位空间,初始值表示和半经典繁殖的准确性
Complexified phase spaces, initial value representations, and the accuracy of semiclassical propagation
论文作者
论文摘要
使用相位空间络合率,在位置空间中的半经典传播器的初始值表示(IVR)作为反向Segal-Bargmann(S-B)变换的组成,对半经典相干态传播器的变换。结果表明,结果不含苛性奇异性,与Herman-Kluk(H-K)传播器相同,在物理和化学应用中发现了无处不在。我们将该特定IVR的理论方面与Van Vleck-Gutzwiller(VV-G)传播器及其IVR之一进行了对比,它通常用于逃避VV-G所需的轨迹的非线性“根系搜索”。我们证明,除了H-K繁殖器以外,绕过根搜索是以严重的数值不稳定的代价。我们使用均匀的Kerr系统进行的全面数值计算来备份理论论点,我们还揭示了一些意外的新现象,即:(1)观察半经典动力学中Ehrenfest时间的一半明确标记; (2)围绕苛性剂的轨迹的积累是时间增加的函数(称为“苛性粘性”)。我们期望这些现象比仅Kerr系统更一般。
Using phase-space complexification, an Initial Value Representation (IVR) for the semiclassical propagator in position space is obtained as a composition of inverse Segal-Bargmann (S-B) transforms of the semiclassical coherent state propagator. The result is shown to be free of caustic singularities and identical to the Herman-Kluk (H-K) propagator, found ubiquitously in physical and chemical applications. We contrast the theoretical aspects of this particular IVR with the van Vleck-Gutzwiller (vV-G) propagator and one of its IVRs, often employed in order to evade the non-linear "root-search" for trajectories required by vV-G. We demonstrate that bypassing the root-search comes at the price of serious numerical instability for all IVRs except the H-K propagator. We back up our theoretical arguments with comprehensive numerical calculations performed using the homogeneous Kerr system, about which we also unveil some unexpected new phenomena, namely: (1) the observation of a clear mark of half the Ehrenfest's time in semiclassical dynamics; and (2) the accumulation of trajectories around caustics as a function of increasing time (dubbed "caustic stickiness"). We expect these phenomena to be more general than for the Kerr system alone.