Photonically Integrated Cold Atom Sources (Picas)

We present a compact optical delivery design for a 2D+ MOT used with a magnetic assembly and a commercial vacuum piece to create a standardised cold atom source. Picas provides a plug-and-play system, free of optical alignment, capable of producing an atomic flux of >1e9 atoms per second with <50mW of laser power. The dimensions of the system are 67mm x 67mm x 112mm (W x H x L), where such compactness is achieved through a fixed optical design, additive manufacturing techniques, and a novel beam expansion method that forms a multiply split cylindrical beam.

Timothy Ballance, David Bowman, Will McGrath, Max Perez, "Picas: Photonically Integrated Cold Atom Source," Proc. SPIE 11578, Cold Atoms for Quantum Technologies, 115780F (4 October 2020); https://doi.org/10.1117/12.2583877

All existing pressure standards (classical and quantum-based) are large apparatuses - typically, the size of a van or larger. In this thesis, we report on the progress towards building a portable version of a cold-atom based pressure standard which can easily transported by a van instead. Specifically, we discuss - the flexible laser design that can produce 780 nm pump light anywhere in a 26 GHz range and repump light anywhere in a +/- 6.8 GHz range within <1 MHz with no realignment. - the magnetic field coils that can produce gradients in excess of 400 G/cm without changing temperature (provided that >14 mL/s of 10 C to 15 C water is available. - the low-outgassing vacuum chamber that can supply rubidium for measurement while minimizing contamination in the chamber under test. - preliminary results characterizing the performance of its rubidium source and magneto-optical trap. - future plans for the apparatus. This pressure standard leverages the linear relationship between the pressure of a vacuum.

Waldock, P. A. Z. (2022). Progress towards a portable cold-atom pressure standard (T). University of British Columbia. Retrieved from https://open.library.ubc.ca/collections/ubctheses/24/items/1.0421366

Optical tweezer arrays have revolutionized atomic and molecular physics, forming the backbone of key experiments in quantum computing, simulation, and metrology. This technique's simplicity in single-particle control and detection allows trapping tens to hundreds of atomic qubits. Recently, arrays with around one thousand atoms have been achieved, although scaling to thousands of qubits with long coherence times and high-fidelity imaging remains a challenge, crucial for quantum error correction applications. They experimentally realized an optical tweezer array trapping over 6,100 neutral atoms in around 12,000 sites, surpassing state-of-the-art performance metrics. We achieved a record coherence time of 12.6 seconds for hyperfine qubits, a trapping lifetime close to 23 minutes in a room-temperature apparatus, and an imaging survival rate of 99.98952% with an imaging fidelity over 99.99%. These advancements suggest that universal quantum computing with ten thousand atomic qubits could be imminent and pave the way for large-scale quantum simulation and metrology experiments.

Manetsch, H. J., Nomura, G., Bataille, E., Leung, K. H., Lv, X., & Endres, M. (2024). A tweezer array with 6100 highly coherent atomic qubits. ArXiv. /abs/2403.12021