Operating ferrimagnet as terahertz antiferromagnetic spin-torque oscillator

ORAL

Abstract

Ultrafast dynamics is a great promise of antiferromagnetic (AFM) spintronics, but AFM materials are hard to detect due to vanishing magnetization. A plausible alternative is to use ferrimagnets (FIMs) that can be operated as AFM with high frequency while detected as simple ferromagnets. We investigate how the terahertz spin-torque oscillator previously proposed in AFM can be implemented in FIMs without losing its essential merits. We find that anti-damping torques can trigger spontaneous oscillation of the exchange mode in FIMs, resembling the terahertz AFM spin dynamics. While sustaining an auto-oscillation of AFM requires dynamic feedback, an FIM oscillator can stabilize on its own. This unique feature remarkably simplifies the experimental realization.

*This work is supported by the Air Force Office of Scientific Research under grant FA9550-19-1-0307.

–

Presenters

  • Ran Cheng

    • University of California, Riverside
    • Electrical and Computer Engineering, University of California, Riverside
    • Department of Electrical and Computer Engineering, University of California, Riverside
    • University of California - Riverside

Authors

  • Hantao Zhang

    • Electrical and Computer Engineering, University of California, Riverside
    • University of California, Riverside
    • Department of Electrical and Computer Engineering, University of California, Riverside

  • Mingda Guo

    • Physics and Astronomy, University of California, Riverside
    • University of California, Riverside

  • Ran Cheng

    • University of California, Riverside
    • Electrical and Computer Engineering, University of California, Riverside
    • Department of Electrical and Computer Engineering, University of California, Riverside
    • University of California - Riverside