Magnon dispersion and magneto-optical Kerr effect of antiferromagnetic L1<sub>0</sub>-type MnPt

ORAL

Abstract

Antiferromagnetic (AFM) materials are attracting attention due to weak response to external magnetic fields and fast spin dynamics in the THz frequency range. In particular, high Néel temperature AFM materials may be great candidates for future spintronic devices. We use first-principles calculations based on density functional theory and the spin spiral approximation to study the magnon dispersion of AFM L10-type MnPt. Néel temperatures computed using the mean-field/random-phase approximation are 1.12%/20.9% smaller than experimental results. For studying the magneto-optical Kerr effect (MOKE), a fully relativistic band structure and dielectric tensor are computed. We simulate the change of the MOKE signal under magnetization on the order of 3.98µB per unit cell by spin flipping and tilting. Kerr rotation angles increase linearly with magnetization, corresponding to spin tilting, while there is no signal without spin tilting due to compensating AFM spin configuration. Our results show that Kerr rotation is three times larger in the UV region than for visible light.

*Illinois MRSEC NSF DMR-1720633

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Presenters

  • Kisung Kang

    • Department of Materials Science and Engineering, University of Illinois

Authors

  • Kisung Kang

    • Department of Materials Science and Engineering, University of Illinois

  • David Cahill

    • Materials Science and Engineering, University of Illinois at Urbana-Champaign
    • Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana-Campaign
    • University of Illinois at Urbana-Champaign
    • University of Illinois at Urbana–Champaign
    • Department of Materials Science and Engineering and Materials Research Laboratory, Univ of Illinois - Urbana
    • Univ of Illinois - Urbana
    • Univ of Illinois at Urbana-Champaign
    • Department of Materials Science and Engineering, University of Illinois

  • Andre Schleife

    • University of Illinois at Urbana-Champaign
    • Materials Science and Engineering, Univ of Illinois - Urbana
    • Materials Science and Engineering, University of Illinois, Urbana-Champaign
    • Materials Science and Engineering, University of Illinois - Urbana
    • Department of Materials Science and Engineering, University of Illinois
    • Univ of Illinois at Urbana-Champaign
    • University of Illinois
    • University of Illinois at Urbana–Champaign