Electrical manipulation of magnetic domain structure in van der Waals ferromagnetic Fe$_3$GaTe$_2$ using ferroelectric PMN-PT single crystal

2D van der Waals (vdW) ferromagnets have emerged as promising materials for spintronic applications due to their unique magnetic properties and tunability. Controlling ferromagnetism via external stimuli is critical for both fundamental research and device integration. In particular, modulation of magnetic anisotropy and exchange interactions through strain offers a viable pathway for functional control. Owing to their weak interlayer coupling, vdW ferromagnets exhibit pronounced sensitivity to strain, enabling effective tuning of their magnetic states. In this study, electric-field-induced magnetoelectric coupling is investigated in the above-room-temperature vdW ferromagnet Fe$_3$GaTe$_2$ integrated on a ferroelectric PMN-PT substrate. It is demonstrated that application of an electric field leads to a substantial reduction in coercive force along with dynamic reconfiguration of the magnetic domain structure. These effects are attributed to electric-field-induced modulation of the vdW interlayer gap and enhancement of the Dzyaloshinskii-Moriya interaction. These findings reveal a strong interplay between electric fields and magnetism in vdW systems, offering a viable route toward the development of low-power, multifunctional magnetic devices. This work establishes a foundation for the electric-field control of magnetic properties in vdW ferromagnets and highlights their potential in next-generation spintronic technologies.