Traditionally in condensed matter physics, the orbital degree of freedom has been regarded quenched. Thus, it has received little attention and overlooked so far, compared to the spin degree of freedom, whose study has become a promising field of spintronics. However, recent works have shown that despite the orbital quenching in the ground state, the orbital information of electrons manifests as an active degree of freedom in transport and dynamic phenomena, in which electrons carry the orbital information. This has given rise to the emergence of a burgeoning field of research, orbitronics, which exploits the orbital degree of freedom of electrons as an information carrier.
In this talk, I aim to deliver the essence of orbitronics – how the field has initiated, what are pivotal concepts, and why it is important. Then I will spotlight major achievements and state-of-the-art of orbitronics, namely orbital Hall effect, orbital Edelstein effect, and orbital torque. These orbitronics phenomena are not only fundamentally important by themselves but also highly useful for spintronics as they provide more efficient ways to manipulate magnetization in broader range of materials. I will explain the theories that I proposed a few years ago and how they have been confirmed by experiments. Despite notable advancements, many fundamental aspects remain shrouded in mystery. In the last part of my talk, I will discuss challenges in orbitronics and present my proposal to overcome these challenges and turn them into opportunities for investigating plethora of new orbitronics phenomena in novel material platforms such as molecular junctions, 2D materials, and oxide heterostructures, in collaboration with members of SPEC.
Coffee and pastries will be served
Peter Grünberg Institute and Institute, Forschungszentrum Jülich