Discrete surface magnons in low-loss epitaxial ferrimagnetic films

ORAL

Abstract

With the growing demand for faster and more energy-efficient data processing, conventional electronics face intrinsic limitations imposed by charge-based transport. Magnons—the quanta of spin waves—provide a promising alternative for low-energy and high-speed information transport, relying on magnetic materials with ultra-low damping. Recently, lithium aluminum ferrite (Li0.5Al1.0Fe1.5O4, LAFO), a ferrimagnetic insulator, has been found to exhibit ultra-low damping. Here, we investigate magnons in LAFO films of various thicknesses using Brillouin light scattering. Distinct magnon modes are observed, with up to three modes detected in 70-nm-thick films. From the magnetic-field dependence of the magnon frequencies, the exchange constant and magnetic anisotropy are extracted. In addition, broad frequency tunability and high group velocity are revealed. These results provide fundamental insights into thermally excited magnons in LAFO and establish a foundation for its application in next-generation magnonic devices.

*All authors gratefully acknowledge funding from the Center for Energy Efficient Magnonics, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences at SLAC National Laboratory under contract DE-AC02-76SF00515. J. Tong and X. Li also acknowledge partial support from the Welch Foundation Chair F-0014 for materials supply.

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Presenters

  • Xiangcheng Liu

    • The University of Texas at Austin

Authors

  • Xiangcheng Liu

    • The University of Texas at Austin

  • Junwei Tong

    • The University of Texas at Austin

  • Hari Paudyal

    • University of Iowa

  • Lerato Takana

    • Stanford University

  • Katya Mikhailova

    • Stanford University

  • Yuri Suzuki

    • Stanford University

  • Durga Paudyal

    • University of Iowa

  • Xiaoqin Elaine Li

    • University of Texas at Austin