Quantum Brownian motion in a bath of parametric oscillators: A model for system-field interactions.
Quantum Brownian motion in a bath of parametric oscillators: A model for system-field interactions.
复制标题
参量振荡器中的量子布朗运动：系统场相互作用的模型。
DOI：
--
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
A. Matacz
中科院分区：
文献类型：
--
作者：
B. Hu;A. Matacz
量子布朗运动范式提供了一个统一的框架，人们可以看到一些基本的量子统计过程，如退相干，耗散，粒子产生，噪声和波动的相互联系。本文继续了在一般环境中的量子布朗运动的影响泛函形式主义的早期文件中开始的调查。在这里，布朗粒子线性耦合到最一般的含时二次振子的浴。这个参数振荡器的浴minics标量场，而由单个振荡器建模的布朗粒子的运动可以用来描述粒子检测器的行为，量子场模式或宇宙的比例因子。本文的一个重要结果是推导的影响功能，包括噪音和耗散内核的Bogolubov系数，从而设置阶段的影响功能的形式主义处理问题的量子场论在弯曲的时空。这种方法使人们能够追踪统计过程的来源，如退相干和耗散到真空涨落和粒子产生，并反过来赋予量子场过程的统计力学解释。利用这个结果，我们讨论了来自黑洞和来自闵可夫斯基空间中的匀加速观测者以及霍金、昂鲁、吉本斯和霍金发现的德西特宇宙的量子噪声和热辐射的统计力学起源。我们还导出了在初始压缩热态下系统与参激子相互作用的约化密度矩阵的精确演化算符和主方程。这些结果对于半经典宇宙学和引力中感兴趣的系统和过程的退相干和反反应研究是有用的。我们的模型和结果也有望对量子光学中的相关问题有所帮助。«少
The quantum Brownian motion paradigm provides a unified framework where one can see the interconnection of some basic quantum statistical processes such as decoherence, dissipation, particle creation, noise, and fluctuation. The present paper continues the investigation begun in earlier papers on the quantum Brownian motion in a general environment via the influence functional formalism. Here, the Brownian particle is coupled linearly to a bath of the most general time-dependent quadratic oscillators. This bath of parametric oscillators minics a scalar field, while the motion of the Brownian particle modeled by a single oscillator could be used to depict the behavior of a particle detector, a quantum field mode, or the scale factor of the Universe. An important result of this paper is the derivation of the influence functional encompassing the noise and dissipation kernels in terms of the Bogolubov coefficients, thus setting the stage for the influence functional formalism treatment of problems in quantum field theory in curved spacetime. This method enables one to trace the source of statistical processes such as decoherence and dissipation to vacuum fluctuations and particle creation, and in turn impart a statistical mechanical interpretation of quantum field processes. With this result we discuss the statistical mechanicalmore » origin of quantum noise and thermal radiance from black holes and from uniformly accelerated observers in Minkowski space as well as from the de Sitter universe discovered by Hawking, Unruh, and Gibbons and Hawking. We also derive the exact evolution operator and master equation for the reduced density matrix of the system interacting with a parametric oscillator bath in an initial squeezed thermal state. These results are useful for decoherence and back reaction studies for systems and processes of interest in semiclassical cosmology and gravity. Our model and results are also expected to be useful for related problems in quantum optics.« less