title: Harmonic velocity noise: non-Markovian features of noise-driven systems at long times.
abstract: We propose a harmonic velocity noise with a broadband feature, which is the time derivative of the harmonic noise. If this noise is regarded as a thermal one, the system has a vanishing effective friction and it should induce ballistic diffusion of a free particle at long times. The effective temperature of the system coupled to such a structured heat bath represented by the harmonic velocity noise is introduced. This means that any initial preparation will approach asymptotically a preparation-dependent variance and mean value for velocity variable. Thus the fluctuation-dissipation theorem does not hold as there is no unique stationary state being connected with a breakdown of ergodicity. This noise can show greenness when it is taken as an external noise source to drive a correlation ratchet.
authors.affiliation: Department of Physics, Beijing Normal University, China. jdbao@bnu.edu.cn
authors.forename: Jing-Dong
authors.initials: JD
authors.lastname: Bao
authors.forename: Yan-Li
authors.initials: YL
authors.lastname: Song
authors.forename: Qing
authors.initials: Q
authors.lastname: Ji
authors.forename: Yi-Zhong
authors.initials: YZ
authors.lastname: Zhuo