Approximated center-of-mass motion for systems of interacting particles with space- and velocity-dependent friction and anharmonic potential

TL;DR

This paper introduces an approximate method to analyze the center-of-mass motion in interacting particle systems with complex trapping conditions, validated through simulations and experiments on a magneto-optical trap.

Contribution

It presents a novel dynamical ansatz approach to efficiently study center-of-mass dynamics across various interaction regimes and trap anharmonicities.

Findings

Method accurately predicts center-of-mass motion in models.

Results agree with numerical simulations.

Experimental validation with Rb85 magneto-optical trap.

Abstract

We study the center-of-mass motion in systems of trapped interacting particles with space- and velocity-dependent friction and anharmonic traps. Our approach, based on a dynamical ansatz assuming a fixed density profile, allows us to obtain information at once for a wide range of binary interactions and interaction strengths, at linear and nonlinear levels. Our findings are first tested on different simple models by comparison with direct numerical simulations. Then, we apply the method to characterize the motion of the center of mass of a magneto-optical trap and its dependence on the number of trapped atoms. Our predictions are compared with experiments performed on a large Rb85 magneto-optical trap.