Tunable Room-Temperature Ferromagnetism and Emergent Phenomena in Atomically Thin Transition Metal Dichalcogenide Semiconductors INVITED

Abstract

Our recent discovery of room-temperature ferromagnetism (FM) in transition metal dichalcogenide (TMD) monolayers of VSe2 has triggered intense research efforts by the scientific community [1,2]. However, the VSe2 monolayers are metallic which may not access the rich electronic and optical phenomena open to semiconductors. In this talk, we present a novel approach to induce long-range FM in TMDs through introducing magnetic dopants to form a dilute magnetic semiconductor. We demonstrate the tunability of room temperature FM in semiconducting TMD monolayers (V-doped WS2 and WSe2) [3,4]. Ferromagnetism peaks at an intermediate vanadium concentration of a few atomic percent (2-4 at.% V) and decreases for higher concentrations, which is consistent with quenching due to orbital hybridization at closer vanadium-vanadium distances. We discover a novel thermally induced spin flipping phenomenon in the V-doped WSe2 monolayers [4], and demonstrate the light-mediated FM in the V-WS2 monolayers at room temperature [5]. These findings pave a new pathway for the development of novel spintronic and valleytronic nanodevices based on atomically thin van der Waals magnetic semiconductors and stimulate further studies in this rapidly expanding research field of 2D magnetism.