We investigate memory effects in the spin-boson model using a recently proposed measure for non-Markovian behavior based on the information exchange between an open system and its environment. Employing the numerical exact multilayer multiconfiguration time-dependent Hartree approach, we simulate the dynamics of the spin-boson model at zero temperature for a broad range of parameters. For a fast bath, i.e., in the scaling limit, we find non-Markovian dynamics for a coherently decaying spin at weak system-bath coupling, whereas memory effects are absent for stronger coupling in the regimes of incoherent decay and localization. If the timescales of system and bath are comparable, a complex, nonmonotonic dependence of non-Markovianity on the system-bath coupling strength is observed.

中文翻译：

---

零温度下自旋玻色子模型中的非马尔可夫效应

我们使用最近提出的基于开放系统与其环境之间信息交换的非马尔可夫行为度量来研究自旋玻色子模型中的记忆效应。我们采用数值精确的多层多配置时间相关 Hartree 方法，模拟零温度下自旋玻色子模型的动力学，以获得广泛的参数。对于快速浴，即在标度限制中，我们发现在弱系统-浴耦合下相干衰减自旋的非马尔可夫动力学，而在非相干衰减和定位状态下，强耦合不存在记忆效应。如果系统和浴的时间尺度具有可比性，则观察到非马尔可夫性对系统-浴耦合强度的复杂、非单调依赖性。