Title: Nonlinear Edelstein Effect in Strongly Correlated Electron Systems

Abstract: Nonlinear spintronics, which combines nonlinear dynamics and spintronics, opens a new route for controlling spins and spin dynamics beyond conventional spintronics based on linear responses. Strongly correlated electron systems, which can have large nonlinear responses, are promising candidates for nonlinear spintronics. In this paper, we focus on the nonlinear Edelstein effect (NEE), a generalization of the Edelstein effect, and study the impact of electron correlations on the NEE by performing numerical calculations on a Hubbard model. We find that correlation effects can either enhance or suppress the nonlinear response. We show that the enhancement and suppression of the response are due to the real and imaginary components of the self-energy, respectively. Additionally, we have explored the relationship between the NEE and photomagnetic or optomagnetic effects. Our findings demonstrate that electron correlations can either enhance or suppress the optical spin injection, depending on the light frequency, while always strengthening the inverse Faraday effect.