Contributed Review: The feasibility of a fully miniaturized magneto-optical trap for portable ultracold quantum technology

Abstract

Experiments using laser cooled atoms and ions show real promise for practical applications in quantumenhanced metrology, timing, navigation, and sensing as well as exotic roles in quantum computing, networking and simulation. The heart of many of these experiments has been translated to microfabricated platforms known as atom chips whose construction readily lend themselves to integration with larger systems and future mass production. To truly make the jump from laboratory demonstrations to practical, rugged devices, the complex surrounding infrastructure (including vacuum systems, optics, and lasers) also needs to be miniaturized and integrated. In this paper we explore the feasibility of applying this approach to the Magneto-Optical Trap; incorporating the vacuum system, atom source and optical geometry into a permanently sealed microlitre system capable of maintaining 10 −10 mbar for more than 1000 days of operation with passive pumping alone. We demonstrate such an engineering challenge is achievable using recent advances in semiconductor microfabrication techniques and materials.PACS numbers: 07.07.Df, 37.10.Gh, 07.30.Kf, I. ULTRACOLD QUANTUM TECHNOLOGYSince the first demonstrations of atoms and ions at sub-millikelvin temperatures in the mid-1980s, the field of atomic physics has been revolutionized by laser cooling and trapping as it provides researchers with a method to probe some of the purest and sensitive quantum systems available. This field is still highly productive and recently has put significant emphasis on the practical applications of this technology beyond the laboratory 1,2 . It was evident very early on that ultracold matter would be an indispensable tool in precise timing applications and a recent demonstration 3 has shown extremely low instabilities at the 10 −18 level. The wavelike nature of atoms as they are cooled to lower temperatures can be used to form atomic interferometers that outperform optical counterparts in measurements of accelerated reference frames 4-7 , which are important for inertial guidance systems, but can also provide sensitive measurements of mass, charge and magnetic fields [8][9][10][11] . Greater sensitivity beyond the classical limit is possible via squeezed 12 and entangled states 13-15 , which are also fundamental attributes for quantum computing 16,17 , and long distance quantum networking 18 . Ultracold matter has been used in the emerging field of quantum simulation 19 and is an indispensable tool in determining fundamental constants 20 , testing general relativity 21 and defining measurement standards 22 . Many researchers and industries believe such tools will be a major part of the 'second quantum revolution' in which the more 'exotic' properties of quantum physics are applied for practical applications 23,24 .The field of ultracold matter has reached a matua) m.d.himsworth@soton.ac.uk rity in both experimental methods and theoretical understanding allowing experiments to begin leaving the laboratory 25-27 . These systems are bespoke, rarely take up a ...

Chip-scale atomic devices

“…[304][305][306] A proposal for a chip-based cold atom system was described in Ref. 307 and the reduction of helium permeation into microfabricated cells using appropriate materials has been demonstrated. 118 While much remains to be done in this area, the prospect of a microfabricated platform for the creation and manipulation of laser-cooled atoms is a compelling research direction that could lead to several miniaturized and highly precise instruments for timing and inertial sensing.…”

Hysteresis of noninteracting and spin-orbit-coupled atomic Fermi gases with relaxation

“…Hysteresis loops of noninteracting or spin-orbit coupled ultracold Fermi gases are promising because of recent advance in rapid loading of atoms [67], portable cold atom systems [68], and artificial gauge fields. Although cooling of fermionic systems is challenging, it is also a research field under active investigations.…”

Technologies for trapped-ion quantum information systems

“…One way to address all three problems is to use a cold, isotope-selective [141], stationary source of atoms: a magneto-optical trap (MOT). Though adding some engineering overhead, the MOT is a mature atom-trapping platform [142] that has been integrated with ion traps without excessive technological difficulties [117,118,143].…”