阻尼振子的起伏频谱及扩散系数

Fluctuation Frequency Spectrum and Diffusion Coefficient of Damped Oscillators

本文讨论一个最简单的耗散系统，即一个谐振子与热库耦合的系统。给出Ｌａｎｇｅｖｉｎ力Ｇ（ｔ）及算符ａ（ｔ），ａ￣＋（ｔ）的定义，由此算出阻尼振子的起伏频谱及扩散系数。其结果与Ｗｉｇｎｅｒ－ｗｅｉｓｓｋｏｐｆ近似下求得结果完全一致。

In this paper,we discuss the simplest dissipative system,a harmonic oscillator coupled to enverwment,Which is a bath of harmonic oscillators.We define the Langevin force G(t)and operators a(t) a￣+(t).We calculate the fluctuated frequency spectrum and diffusion coefficient,the result is in agreement with the one's obtained by Weigner Weisskopf approximation.