Compact Cold-Atom Platform Based on Optical Grating and Planar Coil Chips

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.