Piezomagnetic switching of the anomalous Hall effect in an antiferromagnet at room temperature

Piezomagnetism couples strain linearly to magnetic order producing magnetization. Thus, unlike magnetostriction, it enables bidirectional control of a net moment. If this effect becomes large at room temperature, may be technologically relevant, similar its electric analogue, piezoelectricity. To date, however, the studies piezomagnetic have been primarily restricted antiferromagnetic (AF) insulators cryogenic temperatures. Here we report discovery piezomagnetism in metal temperature. Strikingly, by using AF Weyl semimetal Mn$_3$Sn, known for nearly magnetization-free anomalous Hall (AHE), find that an application small uniaxial 0.1 % can both sign and size AHE. Our experiment theory show AHE distinctly from magnetization, which will useful spintronics applications.