Nonthermal magnetization pathways in photoexcited semiconductors

The stabilization of long-range magnetic order in nominally non-magnetic semiconductors using femtosecond light pulses is an exciting yet experimentally challenging goal. Theoretical studies indicate that certain non-magnetic semiconductors can exhibit transient magnetic instabilities following above-gap laser excitation, but the dynamical pathways leading to these states remain largely unexplored. In this work, I introduce a minimal real-time spin-orbital model and simulate the dynamics after an orbital angular momentum kick, identifying the fundamental microscopic mechanisms that enable the emergence of a transient magnetic order and studying the role of dissipation. I then discuss the relevance of these findings for real materials employing a phenomenological time-dependent Ginzburg-Landau model. Finally, I analyze the strengths and limitations of current first-principles methodologies for investigating dynamically induced broken-symmetry states in the light of the present results.