Research Topic: Quantum Devices in Atom Optics

Velocity Selection and Preparation

Recently, we have presented a method to select the velocities of ultra-cold atoms [1] with a modified Fabry-Perot type of device made of two effective barriers and a well, created by blue and red detuned lasers, respectively:

The laser parameters can be used to select the peak and width of the transmitted velocity window. In particular, lowering the central well provides a peak arbitrarily close to zero velocity having a finite width. The low-energy atomic scattering off this laser device was parameterized and approximate formulae were found to describe and explain its behavior using a one-dimensional approximation. We also proposed a procedure to control the average and width of the velocity distribution of ultra-cold atoms by bound-state to resonance conversion [2]. The atom is set initially in a bound state of an optical trap formed by an inner red detuned laser and an outer blue detuned laser. The bound state is later converted into a resonance by a suitable change of the laser intensities.

Our research goal is to propose, improve, extend, and apply the previously found methods. The velocity selection method based on resonances in laser-induced barriers has been also examined using a one-dimensional approximation. It is very important for the experimental application of the idea to go beyond this approximation and examine the device in a three-dimensional case as well as in the case if the device is used in a wave guide. The case of many-particle states will be examined, too.

[1] A. Ruschhaupt, F. Delgado, and J.G. Muga, "Velocity selection of ultra-cold atoms with Fabry-Perot laser devices: improvements and limits", Journal of Physics B: At. Mol. Opt. Phys. 38 (2005) 2665-2674.
[2] F. Delgado, J. G. Muga, and A. Ruschhaupt, "Preparation of ultralow atomic velocities by transforming bound states into tunneling resonances", Physical Review A 74 (2006) 063618.

Last modified: Wed, 13 Oct 2010

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Edited by Andreas Ruschhaupt