The interdisciplinary research in IRG-MAX (Metallic Antiferromagnets and the eXcitations) is designed to advance understanding of the synthesis-structure-property relationships of metallic antiferromagnetic materials. Our key goal is to answer open questions concerning the coupling of magnetic order, optical fields, electronic excitations, and lattice vibrations that underlie fundamental limits on the control of magnetization dynamics using ultrafast optics, fast temperature excursions, and ultrafast currents of heat and charge. Antiferromagnetic order cannot be switched with an external magnetic field. Recent experiments and theory have demonstrated, however, that antiferromagnetic order can be manipulated by spin-orbit-torques generated by charge currents and optical excitation by circularly polarized light. The fundamental time-scales of magnetization dynamics in antiferromagnets are thought be two orders of magnitude faster than in ferromagnets, but have not yet been observed. We focus on metals due to their high electrical and thermal conductivities, and strong interactions of electrons, spin, and phonons.

New Material and new science:

Advance understanding and control of metallic antiferromagnets (AF)

1. Zero net magnetization is both a challenge and an opportunity for science and technology
2. Higher density, faster, more robust than ferromagnetic domains
3. THz sources and detectors
4. Why now? Spin orbit torques provide a new approach for manipulating AF order