A dynamic magneto-optical trap for atom chips

TL;DR

The paper introduces a novel dynamic magneto-optical trap designed for atom chips with limited optical access, using synchronized pulsing of fields and a planar mirror to achieve compactness and efficiency.

Contribution

It presents a new switching-MOT technique that operates with minimal optical access and no external coils, enabling more integrated and compact atom chip systems.

Findings

Captures 2 million atoms of $^{85}$Rb

Achieves cooling below Doppler temperature

Uses a planar mirror for beam geometry

Abstract

We describe a dynamic magneto-optical trap (MOT) suitable for the use with vacuum systems in which optical access is limited to a single window. This technique facilitates the long-standing desire of producing integrated atom chips, many of which are likely to have severely restricted optical access compared with conventional vacuum chambers. This "switching-MOT" relies on the synchronized pulsing of optical and magnetic fields at audio frequencies. The trap's beam geometry is obtained using a planar mirror surface, and does not require a patterned substrate or bulky optics inside the vacuum chamber. Central to the design is a novel magnetic field geometry that requires no external quadrupole or bias coils which leads toward a very compact system. We have implemented the trap for $^{85}$Rb and shown that it is capable of capturing 2 million atoms and directly cooling below the Doppler temperature.