Piezomagnetic transport in van der Waals noncoplanar Antiferromagnets

Abstract: The piezomagnetic effect-strain-induced linear modulation of magnetization, arises in magnets with broken time-reversal symmetry (BTRS), offering a pathway to bidirectional strain-based control of magnetism, which is an essential straintronic and spintronic functionality in solids. Metallic antiferromagnets with BTRS provide an ideal platform to study this effect through transport measurements, yet experimental demonstrations are limited. Van der Waals (vdW) nanomagnets, with their mechanical flexibility, are particularly promising for realizing large piezomagnetic responses and effective transport control. Here we demonstrate piezomagnetic control of electronic transport in nano-devices of the vdW antiferromagnets CoNb$_3$S$_6$ and CoTa$_3$S$_6$, archetypal vdW metals with BTRS that exhibit a spontaneous Hall effect. Applying uniaxial strain linearly modulates both the antiferromagnetic transition temperature and coercive field, consistent with strain-driven tuning of exchange coupling, key signatures of the piezomagnetic effect. Moreover, spontaneous Hall effect is controllable via strain, evidencing piezomagnetic tuning of Berry curvature and its associated geometric transport. These findings establish piezomagnetism as a powerful route to manipulate antiferromagnetic transport, opening avenues for straintronic and spintronic applications in vdW magnetic systems.