In the drive to develop cold-atom quantum technologies, compact vacuum systems are key to enabling quantum sensing for real world applications. These vacuum systems not only have to be reduced in size, weight, and power compared to their traditional counterparts, but face other challenges. Eliminating active pumping addresses both size and power, but introduces the issue of helium gas permeation as passive vacuum pumping techniques do not remove noble gases. Here we present a centilitre-scale vacuum cell, constructed from low helium permeable materials, with an integrated grating magneto-optical trap optic. A robust cold-atom demonstrator is described, loading 107 s-1 laser-cooled 87Rb, with 12 W of electrical power through a USB battery and optical power delivered by fibre. Under active vacuum pumping, with continuous Rb gas emission, a pressure equilibrium of 10-7 mbar is achieved. With purely passive vacuum pumping the pressure stabilises to 3 x 10-6 mbar with a 17-day time constant, and has been demonstrated to work for two years with only passive vacuum pumping. This research continues to advance and will enable a wide range of cold-atom quantum sensors.
Appl. Phys. Lett. 119, 124002 (2021); doi: 10.1063/5.0061010
|Dr. Oliver Burrow