Abstract: The functionality of nematic liquid crystals lies in that their optical properties are linked to a controllable orientation of underlying nematic directors. In analogy, electronic nematicity refers to a state whose electronic properties spontaneously break rotation symmetries of the host crystalline lattice. In this work, through the study of resistivity anisotropy, we show that the ground state of a layered antiferromagnet CoTa3S6 exhibits a switchable nematicity within its antiferromagnetic order, and that the electronic nematic order can be manipulated by in-plane magnetic field as well as in-plane strain, while a strong memory effect is shown for the former. We also show that the presence of both strain and in-plane magnetic fields can further modulate the writing of the nematic order. Remarkably, we find that the broken three-fold rotation symmetry is recovered with a moderate out-of-plane field, calling for a complex interplay between the reported non-coplanar tetrahedron spin orders [1] and electronic nematicity in the system. Our study establishes CoTa3S6 as an antiferromagnetic platform with highly tunable and rich functionalities based on an interplay between broken rotation and time reversal symmetries.
[1] Takagi et al., 19, 961–968, Nat. Phys. (2023); Park et al., Nat. Comm. 14, 8346, (2023)