We present compact, robust cold-atom platforms based on grating MOTs, highlighting recent innovations in gMOT technology, their integration with vacuum systems, and how these simplified systems are being applied to quantum sensing applications.
Cold and ultracold states of matter have great potential to enable and disrupt applications of information science, sensing, navigation, and timekeeping. In this talk, we will explore several exciting topics within the cold atom quantum sensor space, including context for the specific challenges and relevant technologies that enable sensing applications on cold atom platforms. To successfully transition these states of matter from pure science to out-of-the-laboratory critical engineering tools, it is necessary to simplify, stabilize--and ultimately commercialize--the building blocks of cold atom systems. We present enabling technologies to address the technical challenges of preparing cold atom-based systems.
Cold atoms produced in magneto-optical traps (MOTs) have underpinned advances in emerging quantum technologies, including quantum computing, precision metrology, and fundamental physics. Grating-based MOT (gMOT), which employs a reflective diffraction grating to enable laser cooling from a single incident beam, offers a compact alternative to conventional six-beam MOTs. However, the inherent asymmetry of gMOT beam geometry can compromise the trapping stability and efficiency, particularly for atomic species with complex internal level structures. Here, we present a geometric-phase dielectric metasurface that simultaneously engineers the transmitted and diffracted wavefronts with desired polarization states, enabling full MOT operation under axial illumination using a single planar optical element. This metasurface-based architecture restores the symmetry in the trapping forces while preserving the compactness and simplicity of gMOTs. Using this approach, we demonstrate the trapping and cooling of cesium─an atomic species widely regarded as challenging for standard gMOT implementations─and analyze the trapping mechanism through numerical calculations. By providing independent control over key trapping parameters within a planar and alignment-simplified platform, this work establishes a route toward compact, robust, and species-flexible cold-atom systems, thereby expanding the applicability of miniaturized MOTs for integrated quantum technologies.
Abstract We present a compact cold atom platform where an optical grating chip and planar coil chip are placed inside a compact vacuum chamber to create a magneto-optical trap. This approach significantly reduces the system volume to about 20 × 20 × 20 cm3 compared to conventional vacuum systems and offers greater flexibility in accessing the trapped atoms. We demonstrate the trapping of 3 × 105 cold rubidium atoms at a temperature of 100 μK in a vacuum pressure below 10−7 mbar. The simplified optical geometry, low power consumption, and high degree of integration make this a promising platform for portable and versatile cold-atom devices in quantum sensing, timing, and information processing.