ZrTe₂/CrTe₂: an epitaxial van der Waals platform for spintronics

The rapid discovery of two-dimensional (2D) van der Waals (vdW) quantum materials has led to heterostructures that integrate diverse quantum functionalities such as topological phases, magnetism, and superconductivity. In this context, the epitaxial synthesis of vdW heterostructures with well-controlled interfaces is an attractive route towards wafer-scale platforms for systematically exploring fundamental properties and fashioning proof-of-concept devices. Here, we use molecular beam epitaxy to synthesize a vdW heterostructure that interfaces two material systems of contemporary interest: a 2D ferromagnet (1T-CrTe₂) and a topological semimetal (ZrTe₂). We find that one unit-cell (u.c.) thick 1T-CrTe₂ grown epitaxially on ZrTe₂ is a 2D ferromagnet with a clear anomalous Hall effect. In thicker samples (12 u.c. thick CrTe₂), the anomalous Hall effect has characteristics that may arise from real-space Berry curvature. Finally, in ultrathin CrTe₂ (3 u.c. thickness), we demonstrate current-driven magnetization switching in a full vdW topological semimetal/2D ferromagnet heterostructure device.