Electrically tunable moir\'e magnetism in twisted double bilayers of chromium triiodide

TL;DR

This paper demonstrates electrically tunable moiré magnetism in twisted double bilayers of CrI3, revealing controllable magnetic states influenced by twist angle, temperature, and electrical gating, with potential for advanced magnetic device applications.

Contribution

It introduces the first demonstration of electrically tunable moiré magnetism in twisted double bilayers of CrI3, showing control over magnetic states via twist angle, temperature, and voltage.

Findings

Coexistence of antiferromagnetic and ferromagnetic order observed.

Magnetic states are tunable over a wide range of twist angles.

Voltage-assisted magnetic switching demonstrated.

Abstract

Moir\'e superlattices in van der Waals structures can be used to control the electronic properties of the material and lead to emergent correlated and topological phenomena. Its first demonstration in van der Waals magnets exhibited noncollinear states and domain structures with, however, limited manipulation. Here we report electrically tunable moir\'e magnetism in twisted double bilayers - that is, a bilayer plus a bilayer with a twist angle between them - of layered antiferromagnet CrI3. Using magneto-optical Kerr effect microscopy, we observe the coexistence of antiferromagnetic and ferromagnetic order with nonzero net magnetization - a hallmark of moir\'e magnetism. Such magnetic state extends over a wide range of twist angles (with transitions at around 0{\deg} and above 20{\deg}) and exhibits a nonmonotonic temperature dependence. We further demonstrate voltage-assisted magnetic switching. The observed nontrivial magnetic states and unprecedented control by twist angle, temperature and electrical gating are supported by the simulated phase diagram of the moir\'e magnetism.