Magnetism-induced second-order nonlinear optical responses in multiferroic BiFeO3

作     者：Prasad, Babu Baijnath Liu, Guan-Fu Guo, Guang-Yu 

作者机构：Department of Physics Center for Theoretical Physics National Taiwan University Taipei10617 Taiwan Nano Science and Technology Program Taiwan International Graduate Program Academia Sinica Taipei11529 Taiwan Physics Division National Center for Theoretical Sciences Taipei10617 Taiwan 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2024年

核心收录：

主　　题：Gallium arsenide 

摘      要：Nonlinear optical (NLO) responses of noncentrosymmetric nonmagnets have drawn a lot of attention in the past decades because of their significance in materials characterization, green energy and device applications. On the other hand, magnetism not only can break the inversion symmetry in centrosymmetric crystals but also introduce novel NLO phenomena in noncentrosymmetric materials, thus enabling the magnetic field control of light-matter interactions. However, the magnetism-induced NLO responses have rarely been studied so far. In this paper, we first extend the numerical calculation friendly formula by Rashkeev et al. [Phys. Rev. B 57, 3905 (1998)] for second harmonic generation (SHG) in nonmagnetic materials to include magnetic systems and then calculate the magnetism-induced NLO responses of bismuth ferrite (BiFeO3), a multiferroic that exhibits both ferroelectricity and antiferromagnetic (AFM) ordering at room temperature and has a band gap that falls in the visible frequency region. First, we find that the calculated magnetism-induced SHG susceptibilities are large and the SHG intensity is tunable with the reversal of magnetization. In particular, the interference between crystallographic SHG and magnetically induced SHG components results in a strong magnetic contrast of the SHG signal of ∼440% at SHG photon energy of 4.82 eV, thus enabling a magnetic control of the SHG in multiferroic BiFeO3. Also, because of the sensitivity of the SHG signal to the direction of the Néel vector, the SHG can be utilized to detect the reversal of the Néel vector in the AFM materials, which is an important issue for AFM spintronics. Second, the calculated bulk photovoltaic effects (BPVE) in BiFeO3 are also strong, being larger than some well-known NLO compounds such as BaTiO3, GaAs, CdS and CdSe. Finally, we analyse the origins of the prominent features in the NLO response spectra in terms of the calculated quantum geometric quantities. Our interesting findings suggest that th