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Zong-Yuan Ge

Publications and source records attributed to Zong-Yuan Ge.

3 recordsLinked to original sources

End-to-End Learning of Quantum Control on Latent Dynamical Manifold

Traditional quantum control relies on an iterative "simulate-then-optimize" paradigm, where dynamics simulation and control design are decoupled, leading to substantial computational overhead and limited scalability, particularly in noisy environments. Here, we propose an end-to-end quantum control framework based on long short-term memory, in which system dynamics and control strategies are learned jointly in a low dimensional latent manifold. The model directly maps initial states and environmental parameters to both dynamical trajectories and optimized control pulse in a single forward pass. The framework is validated on adiabatic speedup in a two-level system and state transfer in a one-dimensional spin chain under noise, achieving accurate dynamical prediction and control optimization. It improves the fidelity for both tasks and significantly reduces the optimization cost by three orders of magnitude compared with conventional iterative methods, while exhibiting strong generalization to multi-parameter, time-varying noise, as well as to different initial states and driving fields. Our work introduces a data-driven control paradigm based on latent manifold learning, reducing the computational bottleneck of iterative optimization and enabling real-time adaptive control of complex open quantum systems.

quant-ph

Realizing leakage elimination operator-based adiabatic speedup on a superconducting quantum processor

The slow evolution required for adiabaticity in adiabatic quantum computation renders the system vulnerable to environmental noise. Leakage elimination operator (LEO) control provides an effective strategy to realize adiabatic speedup over a short timescale, thus mitigating the noise impact. Despite extensive theoretical investigations, the realization of LEO-based adiabatic speedup on realistic superconducting quantum processors remains absent. In this work, we present such a realization on IBM superconducting quantum processors. We first characterize the trade-off between adiabaticity and noise accumulation by varying the total evolution time on both the Qiskit simulator and the ibm_marrakesh processor, employing a comprehensive noise model that closely reproduces the experimental results. We then implement ideal LEO pulse derived for a closed system and achieve a significant enhancement of adiabatic fidelity within a short evolution time. To further improve the adiabatic fidelity, we refine the ideal LEO pulse via Bayesian optimization based on the comprehensive noise model. The optimized pulse yields a modest fidelity gain in simulation, yet on hardware it falls short of the ideal pulse under the present experimental conditions. Our work validates the feasibility of LEO-based adiabatic speedup on a superconducting quantum processor and highlights the potential of LEO for noise-aware adiabatic dynamics.

quant-ph

Enhanced Algorithmic Perfect State Transfer on IBM Quantum Computers

Perfect state transfer (PST) through a spin chain can be theoretically obtained via predesigned PST couplings. However, the corresponding experiment on IBM quantum computers demonstrates low transmission success probability (SP) due to noises. Using few qubits of their 127-qubit Eagle processors, we perform the simulation of algorithmic PST through an XY spin chain with PST couplings on ibm_sherbrooke and ibm_brisbane processors, alongside Qiskit simulations. The peak SP cannot reach 1 ($\sim$0.725 peak SP for N=4). We then propose a comprehensive noise model including Pauli errors, thermal relaxation ($T_1$) and dephasing ($T_2$), and ZZ crosstalk. Based on the experimental parameters provided by the IBM superconducting quantum computing platform, we perform the Qiskit simulation with the comprehensive noise model, and find that the time evolution of the SP is highly consistent with the experimental results. This simulation yields a peak SP of 0.761 at $\textstyle t\approxπ/4$, closely matching the results on hardware. To mitigate the impact of noise, we use rescaling techniques to correct noise-induced time shifts and SP decay, achieving an SP improvement of 0.210 (27.60%) in simulators and 0.263 (38.23%) on hardware, aligning hitting times closer to ideal values. Additionally, optimal couplings designed via grid search and refined by Bayesian optimization under the comprehensive noise model achieve an SP improvement of 0.190 (26.21%) in simulators and 0.056 (7.72%) on hardware. Our work highlights challenges in implementing algorithmic PST on current quantum computers, proposes a comprehensive noise model to effectively describe the system dynamics, and provides insights for developing noise-robust quantum communication protocols.

quant-ph