Welcome to the BEC2 site
BEC2 is the second Bose-Einstein condensation apparatus in our lab, which also utilizes an atom chip in order to manipulate the atomic cloud. One of the advantages of the atom chip is the ability to bring the atoms up to 1µm (and even closer) to the surface of the chip, which leads to high magnetic gradients. In our recent experiments we take a different approach, we keep the BEC ~100μm from the atom chip surface, and we increase the value of the magnetic field in the trap minimum. This change has two main effects: First, the background electro-magnetic noise at the relevant frequency is very low. Second, we can use our 87Rb atom as a pure two level system. We used this system for two different experiments, with thermal atoms or wirh a BEC.
The experiment with thermal atoms investigated the transition rates between different Zeeman sublevels of trapped atoms in the presence of noise. Background noise is usually considered to be “white noise”. We investigated the effect of “colored noise” on the transition rates and found that the shape of the noise affect these rates. For more details see the “Asymmetric Transition” section.
In another experiment we developed a new type of matter-wave beam-splitter. We used monocromatic radiation to create coherent transitions between Zeeman sublevel of a BEC. In this experiment we used the atom chip to create fast, accurate, and strong magnetic gradient pulses and to split a BEC. For more details see the “Stern-Gerlach Interferometer” section.
Interference fringes from a BEC that was split using our FGBS (more details).
Full size image
For other news, see "What's New" section.