Related Experiment Video
Updated: Aug 22, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Path integral approach to Brownian motion driven with an ac force
1Department of Physics, University of Texas at San Antonio, San Antonio, Texas 78249-0697, USA. lychen@utsa.edu
Abstract:
Brownian motion in a periodic potential driven by an ac (oscillatory) force is investigated for the full range of damping constant from the overdamped limit to the underdamped limit. The path (functional) integral approach is advanced to produce formulas for the probability distribution function and for the current of the Brownian particle in response to an ac driving force. The negative friction Langevin dynamics technique is employed to evaluate the dc current for various parameters without invoking the overdamped or the underdamped approximation. The dc current is found to have nonlinear dependence upon the damping constant, the potential parameter, and the ac force magnitude and frequency.
Related Concept Videos
Central-Force Motion
Applications of Line Integrals
Principle of Angular Impulse and Momentum
Principle of Linear Impulse and Momentum for a System of Particles
Notably, internal forces between particles, occurring in equal and opposite collinear pairs, cancel out and are not part of the equation of motion. This exclusion simplifies the...
Line Integrals in Space
Motion Of A Charged Particle In A Magnetic Field
