Theodoros Adamantopoulos
The progress in the field of antiferromagnetic spintronics has been firmly associated with the advantages that antiferromagnets bare for generation of spin currents. On the other hand, orbital currents have recently emerged as a novel paradigm and foundation for the field of orbitronics, which is able to naturally accommodate abundant lighter materials for the purpose of generating currents of angular momentum. While in the field of THz spintronics the generation of spin photocurrents has recently gained interest, still photocurrents of orbital angular momentum remain unexplored. In my talk, I will report on our understanding of specific microscopic mechanisms in antiferromagents and altermagnets which give rise to complex, intertwined spin and orbital physics out of equilibrium. Moreover, I will demonstrate that optical pulses can be used to drive large non-linear photocurrents of angular momentum in antiferromagnets and altermagnets by photospin and photoorbital Hall effects. While latter effects are extremely sensitive to the combined symmetry of the system in spin and real space, I will demonstrate how the orbital properties of altermagnets can be significantly promoted by lowering the crystal symmetry in the system, thus suggesting a way to exploit an interplay between spin and orbital degrees of freedom for tracking the complex dynamics of staggered magnetization during electrical or optical switching.
* Corresponding author: t.adamantopoulos@fz-juelich.de