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Haoyang Nie

Publications and source records attributed to Haoyang Nie.

2 recordsLinked to original sources

A Surrogate model for High Temperature Superconducting Magnets to Predict Current Distribution with Neural Network

Finite element methods (FEM) for high-temperature superconducting (HTS) magnets become time-consuming at larger scales, restricting the rapid optimization of meter-scale REBCO solenoids. In this work, a surrogate model based on a fully connected residual neural network (FCRN) is developed to predict the current density distribution in REBCO solenoids. Trained on datasets generated from FEM simulations by the T-A formulation, the FCRN model is evaluated under both fast ramping and steady-state scenarios, showing a lower validation loss than the fully connected network (FCN). When extrapolating geometric parameters beyond the training set, the model achieves a relative error of below 10 % for magnetization losses in Case 1 and an average error of 1.2 % for the central magnetic field in Case 2. Furthermore, deploying the steady-state surrogate model for rapid magnet design found the optimal solution within the parameter space under constraints, with a relative central magnetic field error of 0.2 % compared to FEM results. With rapid predictions, this surrogate model offers an efficient tool for the intelligent design of large-scale HTS magnets.

cs.LG

Current-driven motion of magnetic domain-wall skyrmions

Domain-wall skyrmions (DWSKs) are topological spin textures confined within domain walls that have recently attracted significant attention due to their potential applications in racetrack memory technologies. In this study, we theoretically investigated the motion of DWSKs driven by spin-polarized currents in ferromagnetic strips. Our findings reveal that the motion of DWSKs is contingent upon the direction of the current. When the current is applied parallel to the domain wall, both spin-transfer torque (STT) and spin-orbit torque (SOT) can drive the DWSK along the domain wall. Conversely, for currents applied perpendicular to the domain wall, STT can induce DWSK motion by leveraging the skyrmion Hall effect as a driving force, whereas SOT-driven DWSKs halt their motion after sliding along the domain wall. Furthermore, we demonstrated the current-driven motion of DWSKs along curved domain walls and proposed a racetrack memory architecture utilizing DWSKs. These findings advance the understanding of DWSK dynamics and provide insights for the design of spintronic devices based on DWSKs.

cond-mat.mes-hall