Non-equilibrium Spin Dynamics in Altermagnetic System

Altermagnetic systems, characterized with an anisotropic non-degenerate energy between spin states, have recently emerged as promising candidates for spintronic devices. In this work, incorporating the phase transition, we investigate the non-equilibrium spin dynamics in the altermagnetic material β-MnO₂ which exhibits a d-wave Zeeman field. We reveal a unique D’yakonov–Perel spin relaxation mechanism for in-plane spins, directly arising from altermagnetism. In addition, we explore the spin Hall effect and demonstrate the vanishing and emergency of finite spin Hall current when the electric field is aligned along the nodal and antinodal points of the d-wave Zeeman field respectively. These results can potentially shed light on experimental and spintronic design.