Writing and deleting skyrmions by electron beam in van der Waals ferromagnet Fe3GeTe2

Magnetic skyrmions are potential candidates for low-power spintronic devices. Recently, skyrmions have been observed in two-dimensional van der Waals ferromagnets, which extends the range of skyrmion hosting materials to atomically thin limit. However, creating and deleting skyrmions at precise locations is still a challenge for practical applications. In this study, we proposed a solution to this problem. Using in situ Lorentz transmission electron microscopy, we investigated magnetic domain structures in Fe3GeTe2 exfoliated single crystal flakes and found that the skyrmions in this sample are of the Néel type. Interestingly, we found that the skyrmions could be created and deleted at specific locations using a focused electron beam. Micromagnetic simulations results agree well with the experimental results, providing insights into the underlying mechanisms. The methods presented in this work can be extended to other skyrmion material systems, thereby advancing the field of skyrmion-based technologies.