Compact Dual-Beam Zeeman Slower Captures Increased Rubidium Flux, Eliminates Window Contamination Within 44cm

The pursuit of high-flux cold atoms presents significant challenges for researchers developing advanced technologies in metrology, computation and simulation. Chen Chen, Kejun Liu, and Dezhou Deng, from Advanced Materials at the Hong Kong University of Science and Technology (Guangzhou), alongside Shuchang Ma and Peng Zhu, address this problem with a newly designed compact Zeeman slower. Their innovative approach utilises two angled laser beams and a capillary-array system to dramatically reduce atomic contamination and increase the capture rate of atoms for downstream applications. The team demonstrates, through both simulation and experiment with rubidium and ytterbium, a substantial improvement in efficiency and reliability within a remarkably compact 44cm design, paving the way for more robust and high-performing cold atom experiments.

This research details a compact design for a dual-beam Zeeman slower, a device used to create intense beams of cold atoms. The innovative design overcomes limitations found in traditional systems by efficiently decelerating atoms across a wide range of velocities and increasing the overall atomic flux. The resulting Zeeman slower measures just 70mm in length and 25mm in diameter, representing a significant reduction in size while maintaining high performance. Experiments using rubidium-87 atoms demonstrate a capture velocity of 230m/s and an atomic flux of 5x 10^10 atoms/s, showcasing substantial improvements in both parameters. This compact, high-flux device is particularly well-suited for applications in precision measurements, atom interferometry, and the development of quantum information processing technologies.

An optimised slower configuration efficiently produces cold atoms for various applications. Traditional single-beam configurations suffer from substantial residual atomic flux, which impacts downstream optical components, increases system size, and reduces operational lifespan due to atomic deposition. This research employs two angled laser beams and a capillary-array collimation system to address these challenges while maintaining efficient deceleration. Simulations using rubidium demonstrate a significant increase in the fraction of atoms captured by a two-dimensional magneto-optical trap when utilising this new configuration.

Cold Atom Beams and Magneto-Optical Trapping

This body of work explores the creation and manipulation of cold atomic beams, focusing on sources, traps, and techniques for achieving increasingly precise control over atomic motion. The research highlights the importance of intense, bright beams of cold atoms for advancements in atomic clocks, quantum simulation, and fundamental physics. Numerous studies detail various techniques for slowing and trapping atoms, including improvements to magneto-optical trap (MOT) designs. These include two-dimensional MOTs, used as a pre-cooling stage to increase atomic density, dual-chamber MOTs designed to separate the slowing and trapping regions for improved performance, and compact MOTs developed for portability and space-based applications.

Beyond MOTs, the research investigates alternative slowing techniques, such as two-stage slowing and crossed-beam slowing, to achieve even lower atomic velocities. Studies cover a wide range of atomic species, including rubidium and sodium. The research also emphasizes the importance of vacuum technology and compatibility, as well as the growing trend of developing cold atom experiments for space, driven by the potential for high-precision measurements and tests of fundamental physics. This work directly supports the development of more accurate atomic clocks and advancements in quantum simulation and computing. The extensive research indicates a mature and active field with a large research community focused on incremental improvements and interdisciplinary collaboration.

Dual-Beam Zeeman Slower Minimizes Window Contamination

This research presents a novel dual-beam Zeeman slower designed to efficiently capture and decelerate atoms for cold atom applications. The team successfully addressed limitations of traditional single-beam systems, specifically the issue of residual atomic flux contaminating optical windows and reducing operational lifespan. By employing two angled laser beams in conjunction with a capillary-array collimation system, they achieved efficient deceleration while substantially minimizing harmful atomic deposition. Experimental validation using both rubidium and ytterbium demonstrated significant improvements in atomic loading into two-dimensional magneto-optical traps and a near-elimination of contamination on optical surfaces.

The design’s compact geometry, measuring just 44cm in length, and scalability to different atomic species represent a substantial advancement for high-flux cold atom experiments. This innovation holds particular promise for the development of portable and reliable quantum technologies, including analogue and digital quantum computers based on neutral atoms, and for enabling precision metrology and gravitational studies in the challenging environment of space. The authors acknowledge that the miniaturization of cold atom systems is crucial for space-based applications, where constraints on size, power consumption, and robustness are particularly stringent. Future work may focus on optimizing the design for operation under launch stresses and long-term space conditions, potentially through the incorporation of optimized permanent magnets for passive field gradients. This work establishes a robust platform for advancing cold atom technology and realizing the potential of portable quantum technologies with enhanced performance and reduced complexity.