arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1708.06503cond-mat.stat-mechcond-mat.mes-hall
收藏

不稳定立方势中的布朗运动与麦克斯韦妖的作用

Brownian motion surviving in the unstable cubic potential and the role of Maxwell's demon

Luca Ornigotti, Artem Ryabov, Viktor Holubec, Radim Filip

摘要:

在高度不稳定的势场中,过阻尼粒子的轨迹发散得如此之快,以至于位置的方差比它的平均值增长得快得多。因此,用矩来描述动态是没有信息的。相反,我们提出并分析了当地直接测量的特点,克服了这一限制。我们讨论的最可能的粒子位置(位置的概率密度的最大值)和本地的不确定性在一个不稳定的立方势,无论是在瞬态制度和在长时间的限制。作为时间和温度的函数,最大值逆着作用力移动。同时,局部不确定性的增加速度不会超过可观察到的变化。在长时间极限下,概率密度自然地达到准平稳形式。我们解释这个过程作为一个稳定通过测量反馈机制,麦克斯韦恶魔,它作为一个熵泵。测量和反馈的规则自然产生于不稳定动力学的基本性质。所观察到的热致效应是不稳定系统所固有的。他们的详细理解将刺激随机引擎和放大器的发展,以及后来的量子对应物。

英文摘要:

Trajectories of an overdamped particle in a highly unstable potential diverge so rapidly, that the variance of position grows much faster than its mean. Description of the dynamics by moments is therefore not informative. Instead, we propose and analyze local directly measurable characteristics, which overcome this limitation. We discuss the most probable particle position (position of the maximum of the probability density) and the local uncertainty in an unstable cubic potential, both in the transient regime and in the long-time limit. The maximum shifts against the acting force as a function of time and temperature. Simultaneously, the local uncertainty does not increase faster than the observable shift. In the long-time limit, the probability density naturally attains a quasi-stationary form. We explain this process as a stabilization via the measurement-feedback mechanism, the Maxwell demon, which works as an entropy pump. Rules for measurement and feedback naturally arise from basic properties of the unstable dynamics. Observed thermally induced effects are inherent in unstable systems. Their detailed understanding will stimulate the development of stochastic engines and amplifiers and later, their quantum counterparts.

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。

↑