> 50 nm orbital relaxation length revealed

Some time ago, I submitted a theory paper that predicts exceptionally long orbital dephasing in ferromagnets:

  • Dongwook Go, Daegeun Jo, Kyoung-Whan Kim, Soogil Lee, Min-Gu Kang, Byong-Guk Park, Stefan Blügel, Hyun-Woo Lee, Yuriy Mokrousov
    Long-Range Orbital Magnetoelectric Torque in Ferromagnets

(Yes, it’s still “Under Review” because the process took time, and I myself also took a lot of time due to many other exciting stuffs on the way.)

Probably soon after I uploaded the preprint (a few months?), Hiroki Hayashi in Kazuya Ando’s group in Keio University has found “striking” result that the orbital relaxation/dephasing lengths seem to go beyond tens of nanometres. The data were nowhere comparable to other similar-type experiments on spin-orbit torques, and I got totally astonished. Although I made the theroetical prediction myself, I could not believe that the length scale of orbital relaxation/dephasing can be this large! This is not a regime that I could even test in numerical simulations. Soon, I became more confident that this signals a previously unnoticed physics, and the underlying mechanism may involve interactions whose energy scale is very robust ~ 1 eV. This is one of the main features of many orbitronic effects driven by the interaction of electronic wave functions with the crystal potential.

Since then, we exchanged several emails, together with Daegeun Jo in Hyun-Woo Lee’s group in POSTECH, and we began to collaborate seriously. Now, all the results from our long discussions are summarized in this paper:

  • Hiroki Hayashi, Daegeun Jo, Dongwook Go, Yuriy Mokrousov, Hyun-Woo Lee, Kazuya Ando
    Observation of long-range orbital transport and giant orbital torque
    Communications Physics 6, 32 (2023)

I especially like this work because publishing this kind of new experimental work requires braveness and confidence in measurements because the data are so different from “conventional” types.

I hope this paper inspires you, and we will be happy to know your opinions (email, skype, conference, in our/your group, etc.)!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s