Atom chips are microfabricated devices for manipulating and probing ultracold gases a few millionths or billionths of a degree above absolute zero. Despite much progress in the field over the past few years, the methods required to load the atoms remain complicated. For example, atoms need to be cooled and trapped far from the surface of the chip and then transported to the chip surface in a series of complex steps that often lead to many of the atoms being lost on the way.
Joseph Cotter and colleagues have now succeeded in integrating magneto-optical traps onto an atom chip by etching pyramid-shaped structures in a silicon wafer. The pyramids provide a way of trapping cold atomic gases directly onto the atom chip. The technique requires only a magnetic field, which can be produced by simple wire structures on the chip itself, and an incident trapping laser to capture atoms from a room temperature vapour.
"The technique is much simpler than existing atom trapping methods and is the first observation of direct cold atom trapping from a background vapour inside a microfabricated structure on an atom chip," Cotter told nanotechweb.org.
And that's not all: it is also easy to make arrays of these devices within the same chip. This allows the researchers to create and probe many individual atom sources at the same time.
The devices could act as single atom and single photon sources, which are important in the field of quantum information processing. "We also intend to use these devices as a starting point for trapping molecules on a chip," said Cotter.
The team are now working on making a single atom source and using the pyramids as part of a fully integrated atom chip.
The work was reported on arXiv.