Description
This simulation presents a simplified model of a magneto-optical trap used to capture and cool atoms to a few millikelvins. The model uses an ensemble of noninteracting gas particles subject to the forces of six laser beams arranged in three counterpropagating pairs. The dynamics are three-dimensional, but the simulation displays the projections of positions and velocities onto the xz plane.
Controls
Adjust the trap parameters, turn the lasers and magnetic field on or off, choose the graph type, and accelerate the simulation when needed.
Physical model
Cooling occurs through the Doppler effect: the laser beams are slightly red-detuned from the resonance frequency, so a moving atom preferentially absorbs photons from the beam opposing its velocity and is slowed during each absorption and spontaneous-emission cycle—the principle behind the laser cooling used to produce Bose–Einstein condensates.
Developers
Marco P. M. de Souza
References
Cassia E. de F. Ladeira,
Computer Simulations: A Simple Model for Atomic Cooling. (Undergraduate thesis in Physics, Federal University of Rondonia, 2019).
View thesisM. Fox, Quantum Optics: An Introduction (Oxford University Press, 2006).