Role of Chirality and Topology in Orbital Angular Momentum

Dongwook Go
Department of Physics, Korea University

Orbitronics explores how the orbital motion of electrons, which has been long overlooked compared to their charge and spin, can serve as a new carrier of information in quantum materials [1]. In recent years, both theory and experiment have established the existence of orbital currents and their potential for controlling magnetism, opening new possibilities for next-generation electronic devices such as magnetic memory [2–4]. Despite this progress, several key challenges remain: how to reliably generate and detect orbital currents, how to make them robust against material imperfections, and how to enhance their efficiency to a practical level.

In this talk, I will present a unifying perspective on these challenges based on three guiding principles: chirality, topology, and quantum geometry. First, I will show how chiral crystal structures naturally give rise to orbital-momentum locking, providing a route to generate orbital currents [5]. Next, I will discuss how certain chiral materials host topological electronic states—what we term orbital chiral fermions—which can stabilize orbital transport [6]. Finally, I will highlight the role of the quantum geometry of electronic wave functions in amplifying orbital responses, offering a pathway toward stronger and more robust effects [7]. I will conclude with an outlook on how these ideas may shape the future of orbitronics and its role in energy-efficient information technologies.

 References

[1] DG et al. Europhys. Lett. 135, 37001 (2021).
[2] DG et al. Phys. Rev. Lett. 121, 086602 (2018).
[3] Y.-G. Choi, D. Go et al. Nature 619, 52 (2023).
[4] D. Jo, DG et al. npj Spintronics 2, 19 (2024).
[5] DG et al. In preparation.
[6] Hagiwara, DG et al. Adv. Mater. 2418040 (2025).
[7] H. Lee, DG et al. arXiv:2603.19875.