Two-dimensional (2D) magnetic van der Waals materials, especially transition metal dichalcogenides (TMDCs), and their heterostructures are emerging candidates for ultralow-power and ultra-compact device applications. Although theory predicts suppression of long-range magnetic order at finite temperatures in such 2D materials, recent experiments have demonstrated the existence of long-range ferromagnetic order in bulk van der Waals materials (e.g., CrI₃) at the monolayer limit [1,2]. However, these materials require cryogenic temperatures or other special protections to function. Therefore, it becomes crucial to have control over their unique atomic- level magnetism at temperatures close to room temperature, at which most of our devices operate. To this end, our recent discoveries of the strong room temperature ferromagnetism in metallic monolayers of VSe₂ grown on van der Waals substrates (graphite, MoS₂) [3] and semiconducting monolayers of V-doped WSe₂ or WS₂ grown on SiO₂ substrates [4,5] have the potential to transform the fields of spintronics, valleytronics and quantum computation. In this talk, I will present the research progress on 2D magnetism, including our new findings of the light-controlled room temperature ferromagnetism in 2D V-doped TMDCs, the tunable exchange bias effect and light-mediated magnetism in VSe₂/MoS₂ heterostructures, as well as the development of a new class of highly sensitive magnetic sensor using a single layer magnet of VSe₂ [6]. Opportunities and challenges in this rapidly expanding research field will be discussed.

About the Speaker

Dr. Phan is Professor of Physics at the University of South Florida. He received B.S., M.S., and Ph.D. degrees in Physics from Vietnam National University (2000), Chungbuk National University – South Korea (2003), and Bristol University – UK (2006), respectively. His research interests lie in the physics and applications of magnetic materials, with an expertise on the development of novel magnetocaloric and magnetoimpedance materials for energy-efficient magnetic refrigeration and smart sensor technologies. He has published more than 280 peer-reviewed journal papers (over 10,000 citations, h-index: 51 from Google Scholar), 7 review papers, 5 book chapters, and 1 text book. Presently, he serves as an Editor for the Journal of Electronic Materials, the Editor for Applied Sciences, the Managing Editor for Journal of Science: Advanced Materials and Devices, and the Editorial Board Member of Nature: Scientific Reports. He has recently been awarded an Honorary Doctoral Degree by Vietnam National University - Hanoi (2021). He was also the recipient of The Two USF Outstanding Faculty Research Achievement Awards (2017, 2019), the recipient of The USF Outstanding Graduate Faculty Mentor Award (2018, HM), and the recipient of The Medal for His International Contribution and Recognition by Vietnam National University - Hanoi (2018). He has delivered plenary, keynote and invited talks at professional meetings on Magnetism and Magnetic Materials (MMM, ICM, APS, MRS, INTERMAG, TMS, ICAM, ICAMR, ISAMMA, IcAUMS) and organized numerous international conferences on Nanomaterials, Energy, and Nanotechnology.