Electric field control of spin-valley polarization and the spin Hall effect in altermagnets
Phys. Rev. B 113, 094427 – Published 12 March, 2026
DOI: https://doi.org/10.1103/tlpw-95yc
Abstract
Altermagnetism offers a unique potential for spintronic applications through its distinctive spin-split band structure and coupling to crystal symmetries. However, achieving electric-field control of spin and valley degrees of freedom remains a fundamental challenge. Here, we develop a spin-group theory framework to systematically identify symmetry conditions for spin-layer coupling in two-dimensional altermagnets. We classify magnetic layer groups that simultaneously support altermagnetism and valley-contrasting layer polarization, enabling electric-field-induced valley splitting and the spin Hall effect. Our predictions are verified by both tight-binding modeling and first-principles calculations on a bilayer, where a perpendicular electric field generates measurable valley polarization and spin Hall current. This work establishes a universal symmetry design principle for electrical control of spin-valley phenomena in altermagnetic materials.
