Gate-tuning of magnetism in a van der Waals magnetic semimetal Cr₃Te₄

The concept of a gate-induced modulation of a quantum state of matter has become more and more popular since the beginning of this century. In particular, a gate control of magnetism has been one of the central topics in this research field, and in fact significant achievements have been published including a recent paper on gate-tunable room temperature ferromagnetism in a van der Waals (vdW) magnetic metal, Fe₃GeTe₂ [1]. However, a material system explored so far has been limited either to magnetic semiconductors or to magnetic metals, whereas gating effects in magnetic semimetals have been largely unexplored despite the unique features of this class of materials associated with the band-crossing points in the momentum space. This peculiar band structure dominates overall magnetic properties (the Curie temperature (T_C), anisotropy, and magnetotransport properties), which underpins the attractiveness of magnetic semimetals. Because the band-structure-driven magnetism in magnetic semimetals should be extremely sensitive to the Fermi level (E_F), magnetic semimetals are one of the most attractive targets for gate control.

Here we report the gating effects in a vdW magnetic semimetal for the first time. We focus on Cr₃Te₄, an emergent vdW magnetic semimetal [2, 3], and unveil its anomalous carrier-dependent ferromagnetism through a series of the ion-gating experiments. In the presentation, we shows the detailed results on the gate-tunable magnetic properties of Cr₃Te₄, including T_C, magnetic anisotropy, and magnetotransport properties. For details of this study, see the preprint at [4].