Direct observation of the full transition from ballistic to diffusive Brownian motion in a liquid

被引：0

作者：

Huang, Rongxin ^{[1
]}

Chavez, Isaac ^{[1
]}

Taute, Katja M. ^{[1
]}

Lukic, Branimir ^{[2
]}

Jeney, Sylvia ^{[2
]}

Raizen, Mark G. ^{[1
]}

Florin, Ernst-Ludwig ^{[1
]}

机构：

[1] Univ Texas Austin, Ctr Nonlinear Dynam, Austin, TX 78712 USA

[2] Ecole Polytech Fed Lausanne, Inst Phys Mat Complexe, CH-1015 Lausanne, Switzerland

来源：

NATURE PHYSICS | 2011年 / 7卷 / 07期

关键词：

HYDRODYNAMIC INTERACTIONS; OPTICAL TWEEZERS; VELOCITY; SUSPENSIONS; PARTICLE;

D O I：

10.1038/NPHYS1953

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

At timescales once deemed immeasurably small by Einstein, the random movement of Brownian particles in a liquid is expected to be replaced by ballistic motion. So far, an experimental verification of this prediction has been out of reach due to a lack of instrumentation fast and precise enough to capture this motion. Here we report the observation of the Brownian motion of a single particle in an optical trap with 75 MHz bandwidth and sub-angstrom spatial precision and the determination of the particle's velocity autocorrelation function. Our observation is the first measurement of ballistic Brownian motion of a particle in a liquid. The data are in excellent agreement with theoretical predictions taking into account the inertia of the particle and hydrodynamic memory effects.

引用

页码：576 / 580

页数：5