Among all terahertz systems that hold potential in bridging the "terahertz gap" between electronics and photonics, antiferromagnetic materials truly stand out because the quantum spin of antiferromagnetic magnons usually play decisive roles in physical processes, providing a natural connection between the spins of electrons and photons, which is essential for device engineering in the terahertz regime. In collaboration with several leading researchers in this emerging frontier, Prof. Ran Cheng co-authored an invited review article in Nature Materials unraveling the changing landscape and future directions in antiferromagnetic spintronics. With the latest progress of coherent antiferromagnetic spintronics, in which Prof. Ran Cheng has been a pioneer theorist, a new chapter of ultrafast devices with transformative functionalities is unfolding. 

Terahertz (THz) fast operation, absence of stray fields, and the existence of distinct spin-wave species are three prominent features why antiferromagnets could preempt the next-generation technology”, said Dr. Cheng, “however, in the existing chapter of antiferromagnetic spintronics, only the first two received enough attention, because the third one relies on well-controlled coherent spin dynamics which is very challenging”. While coherent spin dynamics only aroused attention recently, it is believed to be the key to integrate spintronics with quantum and neuromorphic technologies.

In the review article, Dr. Cheng and his colleagues analyzed a series of pivotal findings in coherent antiferromagnetic spintronics that are trending in this emerging frontier, including spin generation and transport, electrically driven spin rotation, and related ultrafast spintronic effects. These discoveries laid the physical foundation for practical applications yet to come, such as ultrafast nonvolatile memory, ultrafast wave-based computing, and terahertz nano-oscillators.

The team further suggested several research directions that may facilitate ongoing studies and fuel the future of coherent antiferromagnetic spintronics. The team is optimistic that through cooperative efforts from physicists, material scientists and electrical engineers in the near future, the surging field of coherent antiferromagnetic spintronics is expected to accelerate fundamental and practical research towards efficient, ultrafast, and integrated hardware for the next-generation information technologies.

Publication Title: Coherent antiferromagnetic spintronics

Authors: Jiahao Han, Ran Cheng, Luqiao Liu, Hideo Ohno, Shunsuke Fukami

Journal: Nature Materials

URL: https://www.nature.com/articles/s41563-023-01492-6

For more information on Prof. Ran Cheng's research, please visit https://terahertzspin.engr.ucr.edu/