Band-driven switching of magnetism in a van der Waals magnetic semimetal

Magnetic semimetals form an attractive class of materials because of the nontrivial contributions of itinerant electrons to magnetism. Because of their relatively low–carrier-density nature, a doping level of those materials could be largely tuned by a gating technique. Here, we demonstrate gate-tunable ferromagnetism in an emergent van der Waals magnetic semimetal Cr ₃ Te ₄ based on an ion-gating technique. Upon doping electrons into the system, the Curie temperature ( T _C ) sharply increases, approaching near to room temperature, and then decreases to some extent. This non-monotonous variation of T _C accompanies the switching of the magnetic anisotropy, synchronously followed by the sign changes of the ordinary and anomalous Hall effects. Those results clearly elucidate that the magnetism in Cr ₃ Te ₄ should be governed by its semimetallic band nature.