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Hai-Qing Liu

Publications and source records attributed to Hai-Qing Liu.

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Validating a Koopman-Quantum Hybrid Paradigm for Diagnostic Denoising of Fusion Devices

The potential of Quantum Machine Learning (QML) in data-intensive science is strictly bottlenecked the difficulty of interfacing high-dimensional, chaotic classical data into resource-limited, noisy quantum processors. To bridge this gap, we introduce a physics-informed Koopman-Quantum hybrid framework, theoretically grounded in a representation-level structural isomorphism we establish between the Koopman operator, which linearizes nonlinear dynamics, and quantum evolution. Based on this theoretical foundation, we design a realizable NISQ-friendly pipeline: the Koopman operator functions as a physics-aware "data distiller," compressing waveforms into compact, "quantum-ready" features, which are subsequently processed by a modular, parallel quantum neural network. We validated this framework on 4,763 labeled channel sequences from 433 discharges of the tokamak system. The results demonstrate that our model achieves 97.0\% accuracy in screening corrupted diagnostic data, matching the performance of state-of-the-art deep classical CNNs while using orders-of-magnitude fewer trainable parameters. This work establishes a practical, physics-grounded paradigm for leveraging quantum processing in constrained environments, offering a scalable path for quantum-enhanced edge computing.

quant-ph

Equal-Interval Splitting of Quantum Tunneling in Single-Molecule Magnets with Identical Exchange Coupling

The equal-interval splitting of quantum tunneling observed in simple-Ising-model systems of Ni$_{4}$ (3D) and Mn$_3$ (2D) single-molecule magnets (SMMs) is reported. The splitting is due to the identical exchange coupling in the SMMs, and is simply determined by the difference between the two numbers of the spin-down $n_{\downarrow}$ and spin-up $n_{\uparrow}$ molecules neighboring to the tunneling molecule. The splitting may be presented as $(n_{\downarrow}-n_{\uparrow})JS/{gμ_{0}μ_{B}}$, and the number of the splittings follows $n+1$ where $n=n_{\downarrow}+n_{\uparrow}$ is the coordination number. Besides, since the quantum tunneling is heavily dependent on local spin environment, the manipulation of quantum tunneling may become feasible for this kind of system, which may shed new light on novel applications of SMMs.

cond-mat.mes-hall