Topological states and quantum effects in magnonics

In recent years, with the rapid development of the emerging technologies including the internet of things, cloud computing, big data, and artificial intelligence, higher computing capability is required. Traditional semiconductor devices are confronting huge challenges brought by device miniaturization, energy consumption, heat dissipation, etc. Moore’s law which succeeds in guiding downscaling and upgrading of microelectronics is nearing its end. A new information carrier, instead of electrons, is required urgently for information transmission and processing. Spin waves are collectively excited waves in ordered magnets, and the quantized quasi particle is referred to as magnon. The propagation of magnons does not involve electron motion and produces no Joule heating, which can solve the increasing significant issues of heating dissipation in electronic devices. Thus, magnon-based devices have important application prospects in low-power information storage and computing. In this review, we first introduce the recent advances in the excitation, propagation, manipulation, detection of spin waves and magnon-based devices. Then, we mainly discuss the researches of our group. This part is described from four aspects: 1) Chiral magnonics, including the chiral propagarion of magnetostatic spin waves, Dzyaloshinskii-Moriya interaction(DMI)-induced nonreciprocity of spin waves, spin-wave propagation at chiral interface, magnonic Goos-Hänchen effect, spin-wave lens, and magnonic Stern-Gerlach effect; 2) nonlinear magnonics, including three-magnon processes induced by DMI and noncollinear magnetic textures, skyrmion-induced magnonic frequency comb, twisted magnon frequency comb, and Penrose superradiance; 3) topological magnonics, including magnon Hall effect, magnonic topological insulator, magnonic topological semimetal, topological edge states and high-order corner states of magnetic solitons arranged in different crystal lattices; 4) quantum magnonics, including quantum states of magnon, magnon-based hybrid quantum systems, and cavity magnonics. Finally, the future development and prospect of magnonics are analyzed and discussed.