A proposal for continuous loading of an optical dipole trap with magnetically guided ultra cold atoms

TL;DR

This paper proposes a continuous method to load ultra cold atoms from a magnetic guide into an optical dipole trap by decelerating atoms with a magnetic barrier and optical pumping, supported by numerical simulations.

Contribution

It introduces a novel continuous loading scheme combining magnetic deceleration and optical pumping for ultra cold atoms into optical traps.

Findings

Feasibility demonstrated through numerical simulations.

Loading efficiency depends on magnetic and optical parameters.

Scheme applicable to chromium atoms and similar species.

Abstract

The capture of a moving atom by a non-dissipative trap, such as an optical dipole trap, requires the removal of the excessive kinetic energy of the atom. In this article we develop a mechanism to harvest ultra cold atoms from a guided atom beam into an optical dipole trap by removing their directed kinetic energy. We propose a continuous loading scheme where this is accomplished via deceleration by a magnetic potential barrier followed by optical pumping to the energetically lowest Zeeman sublevel. We theoretically investigate the application of this scheme to the transfer of ultra cold chromium atoms from a magnetically guided atom beam into a deep optical dipole trap. We discuss the realization of a suitable magnetic field configuration. Based on numerical simulations of the loading process we analyze the feasibility and efficiency of our loading scheme.