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arXiv · 2309.01965

Strong and nearly 100$\%$ spin-polarized second-harmonic generation from ferrimagnet Mn$_{2}$RuGa

Y. Q. Liu·M. S. Si·G. P. Zhang
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Abstract

Second-harmonic generation (SHG) has emerged as a promising tool for detecting electronic and magnetic structures in noncentrosymmetric materials, but 100$\%$ spin-polarized SHG has not been reported. In this work, we demonstrate nearly 100$\%$ spin-polarized SHG from half-metallic ferrimagnet Mn$_{2}$RuGa. A band gap in the spin-down channel suppresses SHG, so the spin-up channel contributes nearly all the signal, as large as 3614 pm/V about 10 times larger than that of GaAs. In the spin-up channel, $\chi_{xyz}^{(2)}$ is dominated by the large intraband current in three highly dispersed bands near the Fermi level. With the spin-orbit coupling (SOC), the reduced magnetic point group allows additional SHG components, where the interband contribution is enhanced. Our finding is important as it predicts a large and complete spin-polarized SHG in a all-optical spin switching ferrimagnet. This opens the door for future applications.

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Y. Q. Liu, M. S. Si, G. P. Zhang. 2023-09-05. Strong and nearly 100$\%$ spin-polarized second-harmonic generation from ferrimagnet Mn$_{2}$RuGa. https://arxiv.org/abs/2309.01965

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