Modulating magnon transport in ferromagnetic and antiferromagnetic materials
Luqiao Liu, Electrical Engineering and Computer Science, MIT
Abstract.– Spin waves are considered as one of the promising candidates for realizing unconventional computing and information processing. Compared with other forms of waves, spin wave has the advantage of short wavelength, intrinsic nonlinearity, and non-reciprocity. In this talk, I will discuss some of our experimental efforts on developing magnonic structures for these purposes. In the first effort, we demonstrated mutual interactions between magnons and magnetic domain walls in a ferromagnetic thin film, where magnetic domain walls manipulate the phase and magnitude of spin wave, and a strong spin wave, in turn, moves the position of magnetic domain walls . This mutual control mechanism can be used to realize a programmable spin wave phase shifter. In the second effort, I will talk about long-range spin transport in an easy-plane antiferromagnet, where the spin angular momentum propagates via the superposition of two linearly polarized magnon modes . This birefringence-like spin transport in antiferromagnet enables a bi-stable, non-volatile spin-current switch with a 100% on/off ratio. These mechanisms and device structures could be used as building blocks for future magnon-based information processing in the classical and quantum domain.
 “Mutual control of coherent spin waves and magnetic domain walls in a magnonic device”, Science 366, 1121 (2019)
 “Birefringence-like spin transport via linearly polarized antiferromagnetic magnons” Nature Nanotechnology 15, 563 (2020)
Host: Shulei Zhang