Joint seminar - IEEE Magnetics Society and HKUST ECE - Strong magnon-magnon coupling and unidirectional exchange spin waves in magnetic nanostructures
Magnons, the quanta of spin waves, are collective precessions of electron spins in magnetic materials, which do not involve charge motion during propagation, and thus can avoid Joule heating in information transmission, making them potential candidates for the next-generation of low-power electronic devices. In this talk, I will introduce the observation of strong interlayer magnon-magnon coupling in magnetic metal-insulator hybrid nanostructures. A large anticrossing gap up to 1.58 GHz is observed between the ferromagnetic resonance of the metallic nanowires and the in-plane standing spin waves of a low-damping yttrium iron garnet (YIG) film. Using this effect, we also experimentally observe the long-distance propagation of ultra-short-wavelength spin waves with wavelengths as low as 50 nm, and demonstrate the unidirectional behavior of such spin waves. A nanoscale magnonic interferometer can be designed based on the unidirectional spin waves. We also discuss the experimental observation of nonlocal three-magnon scattering between spatially separated magnetic systems. Above a certain threshold power, a CoFeB Kittel magnon splits into a pair of counter-propagating YIG magnons which can be detected by the inverse spin Hall effect. Our results demonstrate the nonlocal detection of two separately propagating magnons emerging from one common source that may enable quantum entanglement between distant magnons for quantum information applications.
Dr. Jilei Chen is currently an associate researcher (PI) and the leader of the magnonics group at the Institute of Quantum Science and Engineering of Southern University of Science and Technology, Shenzhen, China. He has published more than 20 peer-reviewed papers as the first or corresponding author in high-impact journals, such as one in Nat. Nanotechnol., two in Nat. Commun., four in PRL/PRX, two in ACS Nano, one in Appl. Phys. Rev. and one in Nano Lett. His research interests include spintronics, magnonics, microwave magnetics, antiferromagnetics, hybrid magnonic systems, micromagnetic simulations, topological spin textures, and 2D magnets. Dr. Chen received his bachelor’s (2015) and PhD (2021) degrees from Beihang University, China, and was a visiting scholar at École Polytechnique Fédérale de Lausanne, Switzerland. He has recently been nominated as an Emerging Leader 2024 in applied physics by JPhysD, IOP Publishing.
Please contact Prof. Qiming Shao (eeqshao@ust.hk), Chair of IEEE Magnetics Society Hong Kong Chapter