An atom-by-atom assembler of defect-free arbitrary 2d atomic arrays (1607.03042v1)

Abstract: Large arrays of individually controlled atoms trapped in optical tweezers are a very promising platform for quantum engineering applications. However, to date, only disordered arrays have been demonstrated, due to the non-deterministic loading of the traps. Here, we demonstrate the preparation of fully loaded, two-dimensional arrays of up to 50 microtraps each containing a single atom, and arranged in arbitrary geometries. Starting from initially larger, half-filled matrices of randomly loaded traps, we obtain user-defined target arrays at unit filling. This is achieved with a real-time control system and a moving optical tweezers that performs a sequence of rapid atom moves depending on the initial distribution of the atoms in the arrays. These results open exciting prospects for quantum engineering with neutral atoms in tunable geometries.

• The paper presents a deterministic atom-by-atom assembly technique using optical tweezers and spatial light modulators to create defect-free arbitrary 2D atomic arrays.
• It details a method that rearranges atoms from a half-filled disordered state into ordered configurations with filling fractions up to 98% and success rates of 99.3%.
• This scalable and flexible approach paves the way for robust quantum simulators and processors by enabling customizable 2D atomic arrays for exploring many-body quantum phenomena.

Overview of "An Atom-by-Atom Assembler of Defect-Free Arbitrary 2D Atomic Arrays"

The paper "An Atom-by-Atom Assembler of Defect-Free Arbitrary 2D Atomic Arrays" by Daniel Barredo, Sylvain de L, Vincent Lienhard, Thierry Lahaye, and Antoine Browaeys presents a significant advancement in the field of quantum engineering through the precise assembly of neutral atom arrays. Utilizing optical tweezers, the authors demonstrate the deterministic preparation of fully loaded, defect-free two-dimensional arrays of atoms, which can be arranged in arbitrary geometries. This paper contributes to the broader goal of scalable quantum information processing, quantum simulation, and quantum metrology by addressing the challenge of non-deterministic loading traditionally faced in such experimental setups.

Methodology and Results

The authors present a "bottom-up" approach for atom array assembly using optical tweezers and spatial light modulators (SLM) to create arbitrary 2D microtrap configurations. Each trap is designed to capture a single atom, and the system is equipped with a real-time control mechanism to arrange atoms by dynamically moving them into user-defined target configurations. The method leverages a moving optical tweezer, controlled via acousto-optic deflectors, to transport atoms from an initial disordered half-filled arrangement to the desired ordered configuration.

The experimental setup and control system are robust, employing high-numerical aperture optics to focus the trapping laser light, and real-time imaging for atom positioning. The optical tweezers perform sequential atom moves, allowing for filling fractions up to 98% with arrays consisting of approximately 50 atoms, and filling events succeeding with a probability as high as 99.3%. The paper presents statistical analyses showing high reproducibility, with defect-free arrays achieved in 40% of trials for a $5 \times 5$ target array.

Implications and Future Prospects

The implications of this work are substantial for the development of quantum technologies. By achieving high filling fractions and enabling defect-free array preparation, this method facilitates the experimental realization of scalable quantum simulators and information processors. The flexibility in trap geometry paves the way for customized configurations that can mimic complex many-body quantum systems—an essential aspect for quantum simulations aimed at discovering new quantum phenomena or materials.

Theoretically, this work extends the paradigm of quantum control to larger and more complex quantum systems, potentially involving hundreds of individually trapped atoms. This scalability is mainly constrained by laser power and optical aberrations, but further innovations and optimizations could redress these limitations. The assembly method could be refined to minimize trap occupancy time, improving system longevity and stability under experimental conditions.

In conclusion, the authors' ability to deterministically prepare 2D atomic arrays opens new avenues in the paper of neutral atom systems for quantum simulation applications. The research illustrates a practical pathway towards overcoming stochastic loading challenges that have historically impeded progress in this domain, offering a concrete step towards realizing extensive and intricate quantum systems with potential applications across computing, simulation, and precision measurement domains. Future work could explore enhancements in vacuum conditions and algorithmic optimizations to further scale the approach toward larger assemblies.