Marie Fauquembergue | Searcharxiv

arXiv2005

Partially ferromagnetic electromagnet for trapping and cooling neutral atoms to quantum degeneracy

We have developed a compact partially ferromagnetic electromagnet to produce a Ioffe-Pritchard trap for neutral atoms. Our structure permits strong magnetic confinement with low power consumption. Compared to the previous iron-core electromagnet, it allows for easy compensation of remnant fields and very high stability, along with cost-effective realization and compactness. We describe and characterize our apparatus and demonstrate trapping and cooling of Rb 87 atoms to quantum degeneracy. Pure Bose-Einstein condensates containing 10^6 atoms are routinely realized on a half-minute cycle. In addition we test the stability of the magnetic trap by producing atom lasers.

cond-mat.other↗

arXiv2001

A deterministic origin for instabilities in a magneto-optical trap

The paper reports on the observation of a new type of instabilities in the atomic cloud of a magneto-optical trap (MOT). They appear as large amplitude self-oscillations, either periodic or erratic, depending on the parameters. An original model taking into account the shadow effect and an homogeneous distribution of the atoms in the cloud is developped. It allows us to show that these instabilities originate on the one hand from an anomalous Hopf bifurcation, and on the other hand from the extreme sensitivity of the system to noise.

physics.atom-ph↗