Abstract
The multipiezo effect realizes the coupling of strain with magnetism and electricity, which provides a new way of designing multifunctional devices. In this study, monolayer V(2)STeO is demonstrated to be an altermagnet semiconductor with a direct band gap of 0.41 eV. The spin splittings of monolayer V(2)STeO are as high as 1114 and 1257 meV at the valence and conduction bands, respectively. Moreover, a pair of energy degeneracy valleys appears at X and Y points in the first Brillouin zone. The valley polarization and reversion can be achieved by applying uniaxial strains along different directions, indicating a piezovalley effect. In addition, a net magnetization coupled with uniaxial strain and hole doping can be induced in monolayer V(2)STeO, presenting the piezomagnetic feature. Furthermore, due to the Janus structure, the inversion symmetry of monolayer V(2)STeO is naturally broken, resulting in the piezoelectric property. The integration of the altermagnet, piezovalley, piezomagnetic, and piezoelectric properties make monolayer V(2)STeO a promising candidate for multifunctional spintronic and valleytronic devices.