标题： 量子能量衰减和离散浴中的退相干 显示英文标题

标题： Quantum energy decays and decoherence in discrete baths

摘要： 系统粒子的量子平均能量衰减和纯度衰减被研究为离散浴模型组成部分数量的函数。 系统粒子受到两种不同的物理情况：谐振子（HO）和莫尔斯势。 环境（浴）由{\it 有限}个未耦合的 HO 组成，表征结构化浴，在极限$N\to\infty$下假设其具有欧姆、次欧姆或超欧姆谱密度。 对于 N 的非常低值，平均能量和纯度随时间保持恒定，但当 N 为中间值（10<N<20）时开始衰减，在此期间观察到两个不同的时间区间：相对较短时间的两个指数衰减和较长时间的幂律衰减。 在此 N 范围内，短时间发生退相干，预计在较长时间内出现非马尔可夫动力学。 当$N$增加时，能量和相干性迅速衰减，预计会发生马尔可夫动力学。 波包动力学用于确定粒子在系统势中的演化。 显示英文摘要

摘要： The quantum average energy decay and the purity decay are studied for a system particle as a function of the number of constituents of a discrete bath model. The system particle is subjected to two distinct physical situations: the harmonic oscillator (HO) and the Morse potential. The environment (bath) is composed by a {\it finite} number N of uncoupled HOs, characterizing the structured bath, which in the limit $N\to\infty$ is assumed to have an ohmic, sub-ohmic or super-ohmic spectral density. For very low values of N the mean energy and purity remain constant in time but starts to decay for intermediate values (10<N<20), where two distinct time regimes are observed: two exponential decays for relatively short times and a power-law decay for larger times. In this interval of N decoherence occurs for short times and a non-Markovian dynamics is expected for larger times. When $N$ increases, energy and coherence decay very fast and a Markovian dynamics is expected to occur. Wave packet dynamics is used to determine the evolution of the particle inside the system potentials.