Gate-tunable Berry curvature in van der Waals itinerant ferromagnetic Cr7Te8

Abstract

The anomalous Hall effect (AHE) that associated with the Berry curvature of occupied electronic states in momentum-space is one of the intriguing aspects in condensed matter physics, and provides an alternative for potential applications in topological electronics. Previous experiments reported the tunable Berry curvature and the resulting magnetization switching process in the AHE based on strain engineering or chemical doping. However, the AHE modulation by these strategies are usually irreversible, making it difficult to realize switchable control of the AHE and the resultant spintronic applications. Here, we demonstrated the switchable control of the Berry-curvature-related AHE by electrical gating in itinerant ferromagnetic Cr₇Te₈ with excellent ambient stability. The gate-tunable sign reversal of the AHE can be attributed to the redistribution of the Berry curvature in the band structure of Cr₇Te₈ due to the intercalation-induced change in the Fermi level. Our work facilitates the applications of magnetic switchable devices based on gate-tunable Berry curvature.