Prof. Hao Zeng
Department of Physics, University at Buffalo,
The State University of New York, USA
Date & Time: 14:00 - 15:00, April 3rd (Fri), 2026.
Place: 2nd Conference Room, Main Bldg., Sengen.
Self-Intercalated Covalent 2D magnets and heterostructures
Prof. Hao Zeng
Department of Physics, University at Buffalo,
The State University of New York, USA
Abstract:
The realization of two-dimensional van der Waals (vdW) magnets by exfoliation down to the atomic limit has rekindled interest in 2D magnetism. However, most existing research has focused on exfoliated vdW systems, limiting chemical diversity and tunability. In this talk, I will introduce a lesser-explored material class known as covalent 2D magnets. These materials emerge from the self-intercalation of native 3d transition metal cations between layers of transition metal dichalcogenides, forming atomically thin, covalently bonded layered magnets denoted by the chemical formula M1+δX2. The degree of self-intercalation provides a unique mechanism to control exchange coupling, magnetic order, and spin texture. I will begin by discussing the synthesis of these materials, focusing on Cr2Te3, as well as 2D magnet/semiconductor heterostructures. Subsequently, I will uncover a new mechanism underlying the unconventional anomalous Hall effect (AHE) observed in such systems, driven by the nodal structures in the electronic bands modulated by the noncolinear spin texture. Finally, I will discuss how we leverage such a mechanism to realize reversible switching of AHE by solid-state ionic gating.
(Contact)
Yukiko K. Takahashi, Director, Research Center for Magnetic and Spintronic Materials (CMSM)
E-mail: TAKAHASHI.Yukiko[at]nims.go.jp
E-mail: TAKAHASHI.Yukiko[at]nims.go.jp