Important progress in the field of spin wave electronics has been made by Professor Jia Chenglong's research team from the Key Laboratory for Magnetism and Magnetic Material of the Ministry of Education, which belongs to the School of Physical Science and Technology, Lanzhou University. Recently, this team has published a paper entitled "Twisted Magnon Beams Carrying Orbital Angular Momentum" in Nature Communications, an internationally well-known academic journal.
As one of the most important basic physical attributes of materials, magnetism is the cornerstone of modern information society. Spin wave in magnetic ordering structure is considered as an ideal option for data exchange and wave-based computing in the future due to its high frequency, short wavelength and ultra-low energy consumption. However, the existing angular momentum excited or carried by spin waves is too small and its amplitude decays exponentially in the propagation process, making efficiency and accuracy hard to achieve for future application. To overcome that, Professor Jia’s team, with their German collaborators, proposed a new excited state of spin wave—twisted-mognon, which makes it possible for spin waves to carry special orbital angular momentum protected by topology, namely, the intrinsic orbital angular momentum, whose direction is same with that of mognon's spin angular momentum, and thus its value can be obtained arbitrarily without decaying under the damping effect of the system. These physical attributes of Twisted-magnon allow researchers to overcome the intrinsic defects of traditional spin waves, having important theoretical value and promising application prospects.
This research has been funded by General Program(Grant No.11474138) and Key Program (Grant No.11834005) of National Natural Science Foundation of China, Major Scientific Projects（SFB 762, SFB TRR 227) of German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) and Innovative Research Team Plan of the Ministry of Education of China（IRT-16R35) respectively.
( Translated by Wang Shuangshuang, Proofread by Xian Qinghong )