Electrically induced Dzyaloshinskii–Moriya interaction and exchange bias in a van der Waals magnet Cr1.2Te2

The Dzyaloshinskii–Moriya interaction (DMI) is an antisymmetric exchange interaction that favors noncollinear spin configurations and plays an essential role in high-density, low-power magnetic memories. In general, DMI exists in magnetic systems with inversion symmetry breaking and strong spin–orbit coupling. It can also be induced by interface engineering, chemisorption, and so on. However, tailoring DMI by all-electrical means has yet been illustrated so far. In this paper, we report that DMI can be reversibly induced via electrically controlled proton intercalation in van der Waals magnet Cr1.2Te2 nanoflakes, leading to a large topological Hall resistivity up to 0.47 μΩ⋅cm at 3 K. The magneto-ionically coupling induced sizable DMI is further identified by theoretical calculation in the hydrogen intercalated Cr–Te system. In addition, the protonic gated Cr1.2Te2 nanoflakes exhibit large exchange bias effects at low temperatures, suggesting the emergence of antiferromagnetic phase. Our finding establishes that magneto-ionically coupling can not only control the magnetism but also provide an alternative knob to tailor DMI by all-electrical means, allowing for the searching of unconventional magnetic structures in many more two-dimensional (2D) magnets.