Fast and Coherent Transfer of Atomic Qubits in Optical Tweezers using Fiber Array Architecture
Jia-Chao Wang, Zai-Zheng Zhang, Xiao Li, Guang-Wei Wang, Xiao-Dong He, Min Liu, Peng Xu
Abstract
Programmable neutral-atom arrays offer a promising route toward scalable quantum computing, where coherent qubit transfer enables non-local connectivity and reduces resource overhead. However, transfer speed and motional heating remain key bottlenecks for fast and deep quantum circuits. Here, we employ a fiber array neutral-atom quantum computing architecture with site-resolved control of trap depths to realize smooth amplitude exchange between static and moving traps, thereby enabling fast and coherent qubit transfer with ultralow motional heating. With a 10 s in situ transfer between static and moving traps, we obtain a per-cycle heating rate of 0.156(9) K, sustain over 500 cycles with negligible atom loss, and achieve a quantum state fidelity of 0.99992(5) per cycle. For inter-site transfer between two separated static traps, the operation takes 120 s with 0.783(17) K heating per transfer, and remains negligible atom loss for up to 100 repeated cycles with a fidelity of 0.9998(1) per transfer. Furthermore, through experimental studies of parallel transfer, we establish a model that elucidates the relationship between array inhomogeneity and the transfer heating rate. This fast, low-heating coherent transfer capability provides a practical route for improving both speed and fidelity in atom-shuttling based quantum computing.
AI Impact Assessments
(3 models)Scientific Impact Assessment
Core Contribution
This paper addresses a critical engineering bottleneck in neutral-atom quantum computing: the speed and fidelity of coherent qubit transfer between optical tweezer sites. The key innovation is leveraging a fiber array architecture that provides site-resolved, independent control of static trap depths to enable smooth amplitude exchange between static (S-trap) and moving (M-trap) traps. This eliminates the residual perturbation from static traps during extraction — a limitation of prior approaches that lack individual trap depth control — and enables dramatically faster in situ transfer (10 μs) with ultralow motional heating (0.156(9) μK per cycle).
The paper also introduces a Bernstein polynomial-based shortcuts-to-adiabaticity (STA) trajectory that yields a heating scaling of ∝ D²/(ω₀⁷t⁸), which is superior to the constant-jerk (∝ t⁻⁴) and sinusoidal adiabatic (∝ t⁻⁶) trajectories used in prior work. This theoretical and experimental contribution is significant for optimizing atom transport in general.
Methodological Rigor
The experimental methodology is generally sound and well-characterized:
However, some aspects could be stronger:
Potential Impact
This work is directly relevant to the rapidly advancing field of neutral-atom quantum computing, where companies and groups (Atom Computing, QuEra, Harvard/MIT, Caltech) are racing toward practical fault-tolerant quantum processors. Specific impact areas include:
1. Circuit speed: Reducing atom transfer time from hundreds of microseconds to ~120 μs (inter-site) directly improves quantum error correction cycle rates, which is critical for fault tolerance.
2. Circuit depth: The ability to sustain >500 in situ transfer cycles and ~100 inter-site transfer cycles without significant atom loss enables deeper circuits.
3. Architecture design: The fiber array approach with site-resolved trap control offers a distinct architectural paradigm compared to SLM-based or crossed-AOD approaches, with natural scalability to 3D photonic waveguide platforms.
4. Transport optimization: The STA trajectory with t⁻⁸ scaling provides a concrete improvement over commonly used trajectories, applicable broadly to any atom-shuttling scheme.
The practical impact is somewhat limited by the current scale (6 traps) and the identified bottleneck of fiber array fabrication non-uniformity. The proposed solution (femtosecond laser-written 3D waveguides) is forward-looking but undemonstrated.
Timeliness & Relevance
This paper is highly timely. Neutral-atom quantum computing is experiencing rapid progress, with recent demonstrations of logical qubit operations (Bluvstein et al. 2024, 2026) and fault-tolerant protocols (Reichardt et al. 2025). Atom shuttling speed and fidelity are widely recognized as key bottlenecks — the Manetsch et al. 2025 (Nature) work on AI-optimized transfers is a direct competitor/comparator. This paper offers a complementary and potentially superior approach through hardware-level control (fiber array architecture) rather than software optimization alone.
Strengths
Limitations
Overall Assessment
This is a solid experimental paper that makes meaningful contributions to a critical problem in neutral-atom quantum computing. The combination of fiber array architecture with STA-optimized transfer protocols yields impressive single-atom performance metrics. The work would benefit from larger-scale demonstrations and integration with entangling operations to fully establish practical impact.
Generated Apr 10, 2026
Comparison History (43)
Paper 2 addresses a critical bottleneck in scalable neutral-atom quantum computing: fast, high-fidelity qubit shuttling. By achieving unprecedented fidelities (0.99992) and ultra-low heating, it provides an immediate, highly practical experimental breakthrough for realizing deep quantum circuits with non-local connectivity. While Paper 1 offers a profound theoretical framework for quantum-classical transitions under noise, Paper 2's direct enablement of scalable quantum hardware presents a more immediate and transformative real-world impact in the rapidly advancing field of quantum hardware engineering.
Paper 1 addresses a fundamental bottleneck in neutral-atom quantum computing (qubit transfer speed and motional heating). By achieving unprecedented fidelity (0.99992) and ultralow heating over hundreds of cycles, it represents a foundational experimental breakthrough that directly enables scalable, fault-tolerant quantum computing architectures, giving it profound long-term impact.
Paper 2 addresses the critical challenge of quantum network interoperability by demonstrating a versatile QFC hub compatible with existing DWDM telecom infrastructure. Its broader impact spans quantum networking, telecommunications, and heterogeneous quantum system integration—a foundational requirement for the quantum internet. While Paper 1 represents an impressive engineering advance in neutral-atom qubit transfer with excellent fidelities, it is more incremental and specific to one quantum computing platform. Paper 2's ability to interface diverse quantum devices across standardized telecom channels has wider cross-field relevance and practical deployment potential.
Paper 2 addresses a critical experimental bottleneck in neutral-atom quantum computing (qubit transfer speed and heating) with impressive, highly relevant metrics (fidelity >0.9999). This practical advancement directly enables scalable quantum architectures. Paper 1, while valuable, offers a theoretical refinement to cryptographic models, which generally has a narrower and less immediate technological impact compared to overcoming significant hardware scaling challenges.
Paper 1 likely has higher impact because it demonstrates a concrete hardware capability—fast, coherent neutral-atom qubit transfer with extremely low heating and very high per-cycle fidelity—addressing a key scalability bottleneck (connectivity/atom shuttling) for near-term neutral-atom quantum computing. The results are quantitative, experimentally validated, and immediately applicable to improving circuit depth and architecture design. Paper 2 is timely and potentially broadly useful, but appears more conceptual/simulation-focused and depends on hardware-specific deployment; similar RL-for-calibration ideas exist, reducing novelty relative to Paper 1’s strong experimental advance.
Paper 2 presents an exponential improvement in the scaling bounds for simulating and learning bosonic systems, moving from polynomial to logarithmic dependency on precision. Such foundational theoretical breakthroughs in complexity and classical simulatability have massive, broad implications across quantum information, quantum optics, and computational physics. While Paper 1 is an outstanding experimental achievement addressing hardware bottlenecks in neutral-atom computing, Paper 2's theoretical leap alters the fundamental assumptions about the computational tractability of physical bosonic systems, granting it a broader and potentially more enduring scientific impact.
Paper 1 offers a fundamental theoretical breakthrough by demonstrating an exponential improvement (from polynomial to logarithmic scaling) in the effective description of bosonic systems. This broad mathematical result fundamentally advances both classical simulation and quantum learning algorithms across various physical systems. While Paper 2 presents a highly impressive and practical experimental advance for neutral-atom quantum computing architectures, Paper 1's exponential complexity improvement provides a deeper, more cross-cutting impact that alters foundational assumptions in quantum information and many-body physics.
Paper 2 likely has higher scientific impact due to direct relevance to scalable neutral-atom quantum computing: it demonstrates ultrahigh-fidelity (≈0.9999) coherent qubit transfer with low heating, many repeated cycles, and a model for parallel transfer limits—immediately useful for deeper circuits and modular connectivity. Its methodological rigor is strong (quantitative heating/fidelity metrics, endurance tests, architecture-level insights) and the application pathway is clear and timely. Paper 1 is novel and conceptually broad for quantum thermodynamics/quantum batteries, but its nearer-term real-world deployment and integration into mainstream quantum tech are less direct.
Paper 1 introduces a broadly applicable, open-source machine learning framework for discovering physical laws from diverse quantum datasets. Its cross-disciplinary approach and accessible software tools offer wider potential for adoption and impact across multiple physics subfields compared to Paper 2, which presents a highly significant but hardware-specific advancement in neutral-atom quantum computing.
Paper 2 demonstrates concrete experimental advances in neutral-atom quantum computing with impressive quantitative results (0.99992 fidelity per cycle, 500+ cycles with negligible atom loss). These practical hardware improvements directly address key bottlenecks in a leading quantum computing platform, with immediate applicability to scaling quantum processors. Paper 1, while intellectually interesting in bridging quantum computing with fluid dynamics, presents a more theoretical/emulation-based approach at moderate Reynolds numbers, with unclear near-term practical viability given current quantum hardware limitations. Paper 2's experimental results are more immediately impactful for the quantum computing community.