Thermally robust spin correlations between two Rb atoms in an optical microtrap.

The complex collisional properties of atoms fundamentally limit investigations into a range of processes in many-atom ensembles. In contrast, the bottom-up assembly of few- and many-body systems from individual atoms offers a controlled approach to isolating and studying such collisional processes. Here, we use optical tweezers to individually assemble pairs of trapped Rb atoms, and study the spin dynamics of the two-body system in a thermal state.

An atomic beam source for fast loading of a magneto-optical trap under high vacuum.

We report on a directional atomic beam created using an alkali metal dispenser and a nozzle. By applying a high current (15 A) pulse to the dispenser at room temperature we can rapidly heat it to a temperature at which it starts dispensing, avoiding the need for preheating. The atomic beam produced is capable of loading 90% of a magneto-optical trap (MOT) in less than 7 s while maintaining a low vacuum pressure of <10(-11) Torr.

Counting atoms in a deep optical microtrap.

We demonstrate a method to count small numbers of atoms held in a deep, microscopic optical dipole trap by collecting fluorescence from atoms exposed to a standing wave of light that is blue detuned from resonance. While scattering photons, the atoms are cooled by a Sisyphus mechanism that results from the spatial variation in light intensity. The use of a small blue detuning limits the losses due to light-assisted collisions, thereby making the method suitable for counting several atoms in a microscopic volume.

Lattice interferometer for laser-cooled atoms.

We demonstrate an atom interferometer in which atoms are laser cooled into a 1D optical lattice, suddenly released, and later subjected to a pulsed optical lattice. For short pulses, a simple analytical theory predicts the signal. We investigate both short and longer pulses where the analytical theory fails.

Acousto-optic modulator based frequency stabilized diode laser system for atom trapping.

We report on an inexpensive commercial laser diode stabilized to the D(2)-line in rubidium using a simple scheme. The linewidth was reduced to 1.3 MHz without an external cavity, making it suitable for laser cooling and trapping.