Presentation Information
[8a-A22-8]First-Principles Study of Magneto-Optical Properties in Half-Metallic and Topological Heusler Compounds for MOSPR Applications
〇(M2)Keishi Takayama1, Muhammad Arifin2, Kohji Nakamura1 (1.Mie Univ., 2.Gadjah Mada Univ.)
Keywords:
Magneto optical,MOSPR,Topological Heusler compounds
Surface plasmon resonance (SPR) is widely used for highly sensitive optical sensing applications [1]. Magneto-optical surface plasmon resonance (MOSPR), which combines SPR with the transverse magneto-optical Kerr effect (TMOKE), enables enhanced sensing through magnetization-dependent optical responses. Heusler compounds are promising MOSPR materials owing to their high spin polarization and tunable electronic structures. However, their TMOKE properties remain insufficiently explored from a first-principles perspective.In this study, the electronic structures and magneto-optical properties of five Heusler compounds (CoFeMnAs, CoFeMnSi, Co2MnAs, Co2MnSi, and Co2MnGa) were investigated using the all-electron full-potential linearized augmented plane wave method within the generalized gradient approximation [2]. The dielectric tensor and TMOKE spectra were calculated using the Kubo formalism. The TMOKE spectra exhibit pronounced energy-dependent peaks associated with spin-polarized interband transitions near the Fermi level. Peak energies were found at 1.10, 1.15, 1.30, 1.35, and 1.40 eV, corresponding to the near-infrared wavelength range of commercially available laser sources. These results suggest that wavelength-selective material design is an effective strategy for MOSPR optimization.Analysis of the dielectric tensor revealed enhanced off-diagonal responses (epsilon_yz) in topological compounds due to strong spin-orbit coupling and band inversion [3]. Consequently, the magneto-optical parameter Q reached 0.043, 0.042, 0.029, 0.069, and 0.111, respectively, exceeding the experimental value reported for Cu/Co multilayers (0.0188) [4]. These results demonstrate the potential of topological Heusler compounds for next-generation MOSPR sensing applications.