Joint ECE and HK EDSSC Chapter Online Seminar Series - Long-distance spin transmission in an antiferromagnetic insulator with easy-plane anisotropy
10:00am - 11:30am
Via ZOOM : https://hkust.zoom.us/meeting/register/tJ0vceqsrjkrHtxHoaQm-mBos0-dwi7ZK0a8

Antiferromagnets (AFMs) recently demonstrate great potentials in efficient spin transport through magnons, providing a new platform for spintronics applications. Easy-plane AFMs, with two linearly polarized magnon eigenmodes that are orthogonal to each other, own unique advantages for low-energy control of ultrafast magnetic dynamics. However, it is commonly conceived that these magnon modes are less likely to transmit spins due to their vanishing angular momentum. In this talk, I will firstly discuss the progress and some remained questions in spin transmission through AFMs. I will present our recent experimental observation that an easy-plane insulating AFM, α-Fe2O3 thin film, can conduct efficient spin transmission over micrometer distance [1]. Remarkably, the spin decay length shows an unconventional temperature dependence that cannot be captured by solely considering thermal magnon scatterings. These observations are interpreted by the interference of two linearly polarized propagating magnons, which is an analog to the birefringence effect in optics. Finally, our devices can realize a bi-stable spin-current switch with a 100% on/off ratio under zero remnant magnetic field, providing additional opportunities for nonvolatile, low-field control of spin transport in AFM systems.


[1] Han et al. Nature Nanotechnology 2020 (in press).

When
Time
10:00am - 11:30am
Where
Via ZOOM : https://hkust.zoom.us/meeting/register/tJ0vceqsrjkrHtxHoaQm-mBos0-dwi7ZK0a8
Event Format
Speakers / Performers:
Mr. Jiahao HAN
Massachusetts Institute of Technology

Jiahao Han is a PhD candidate at the Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology (EECS, MIT) and a member of the Spintronic Material and Device Group led by Prof. Luqiao Liu. He received a Bachelor Degree in Materials Science and Engineering at Tsinghua University in 2016. His research interest includes spin-orbit torque switching with topological materials, magnon transmission and interactions in ferromagnetic and antiferromagnetic systems, etc. He has published first-author papers in Science, Nature Nano, and PRL.

Language
English
Recommended For
Faculty and Staff
PG Students
Organizer
Department of Electronic & Computer Engineering
Contact

Prof. Qiming Shao (e-mail : eeqshao)

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