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arXiv quant-ph/0204133quant-ph
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耗散系统与客观描述:以量子布朗运动为例

Dissipative Systems and Objective Description: Quantum Brownian Motion as an Example

Bassano Vacchini

摘要:

本文考虑了一个微物理模型中测试粒子与环境相互作用的量子动力学半群的生成元结构。相应的主方程在长波长极限下可转化为量子水平上描述布朗运动的Fokker-Planck方程。本文用超算子表示了这个Fokker-Planck方程的结构,给出了与相互作用势有关的两种情况对应的动量扩散系数的显式表达式。这个Fokker-Planck方程给出了量子动力学半群的物理动机生成器的一个例子,它作为时间连续测量理论的起点,允许在量子力学中引入轨道。这一理论实际上已经被应用于问题的布朗运动指的是类似的唯象结构获得的基础上的数学要求。

英文摘要:

A structure of generator of a quantum dynamical semigroup for the dynamics of a test particle interacting through collisions with the environment is considered, which has been obtained from a microphysical model. The related master-equation is shown to go over to a Fokker-Planck equation for the description of Brownian motion at quantum level in the long wavelength limit. The structure of this Fokker-Planck equation is expressed in this paper in terms of superoperators, giving explicit expressions for the coefficient of diffusion in momentum in correspondence with two cases of interest for the interaction potential. This Fokker-Planck equation gives an example of a physically motivated generator of quantum dynamical semigroup, which serves as a starting point for the theory of measurement continuous in time, allowing for the introduction of trajectories in quantum mechanics. This theory had in fact already been applied to the problem of Brownian motion referring to similar phenomenological structures obtained only on the basis of mathematical requirements.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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