Deterministic field-induced switching of Néel vector by 180-degree in collinear antiferromagnets

While antiferromagnetic (AFM) materials emerged as highly promising candidates to achieve high-speed device operations, a conundrum inhibiting their practical applications is reliable detection and deterministic switching of the Néel vector. Recent experiments showed that in transition-metal trichalcogenides (TMTs) with inversion symmetry breaking, a 180-degree rotation of the Néel vector can be distinguished and detected optically through second-harmonic generation microscope. However, it remains open as to deterministically switch the Néel vector by 180-degree in a collinear AFM system without relying on the manipulation of the small net magnetization. Here we propose a hitherto unknown mechanism unique to few-layer TMTs with interlayer sliding (that breaks the inversion symmetry) which enables direct control and deterministic 180-degree switching of the Néel vector via a magnetic field, thanks to a symmetry-induced Dzyaloshinskii-Moriya interaction that imbalances the free energy of 180-degree domains. Confirmed by numerical simulations, our theoretical model provides direct guidance to ongoing experiments in TMTs.