Giant nonlinear magneto-optical Kerr effects from Fe interfaces (invited)

Abstract

Second harmonic generation from magnetic materials is shown to lead to a nonlinear magneto-optical Kerr effect that can be orders of magnitude larger than its linear equivalent. The origin ot this effect can be found in the differences between the linear and nonlinear solutions of the optical wave equations and in the symmetry properties of the corresponding optical tensors. Applications for the study of magnetic surfaces, thin films, and multilayers will be discussed.

Nonlinear Magnetooptical Effects Caused by Piezoelectric Ferromagnetism in F4̄3m-type Prussian Blue Analogues

“…In this work, SHG and MSHG were observed in AM A [M B (CN) 6 ]-type ( F 4̄3 m ) Prussian blue analogues. These observations are remarkable results in the fields of magnetooptics and magnetic materials since reports of bulk MSHG have been limited. 10a,d,, Simultaneously, F 4̄3 m -type Prussian blue analogue-based magnets are proven to be piezoelectric ferromagnets, that is, condensed matter with both piezoelectric and ferromagnetism. Since a variety of F 4̄3 m -type Prussian blue analogues can be prepared, these analogues will open a new avenue in the study of piezoelectric ferromagnets and nonlinear magnetooptics.…”

“…Furthermore, below T C , the magnetic ordering creates a magnetic term (χ ijk (2)mag ). This second-order nonlinear susceptibility term is called the magnetization-induced second harmonic generation (MSHG). , Thus, the enhanced SH intensity below T C is due to the creation of the χ ijk (2)mag term. Since the ferromagnetic phase of Cs I Co II [Cr III (CN) 6 ]·0.5H 2 O is in the I 4̄ m 2 magnetic space group, the nonzero tensor elements in χ ijk (2) are described by the contribution of the χ ijk (2)cry and χ ijk (2)mag , that is, χ xyz (2)cry + χ xyz (2)mag , χ yzx (2)cry + χ yzx (2)mag , χ zxy (2)cry + χ zxy (2)mag (Supporting Information).…”

Symmetry analysis of second-harmonic generation at surfaces of antiferromagnets

“…[15]. Nonlinear optical effects were invoked to explain the behavior of lasers in magnetic fields [16], to investigate high temperature superconductors [17,18], and to study structures composed from alternately ferro-and antiferromagnetically ordered thin films [19]. One of the first theoretical investigations of the possibility to apply nonlinear optics to antiferromagnetism was performed by Kielich and Zawodny [20].…”

Measurement of the Resonant Magneto-Optical Kerr Effect Using a Free Electron Laser

“…In the visible range, MSHG is often used, as shown in Figure 3. Through a polarization analysis of the SHG signal, a large-scale rotation was observed in the visible range [66]. Because second-order nonlinear signals only appear from systems without inversion symmetry, the nonlinear RMOKE technique can provide element-selective and surface/interface-selective measurements, which is important for investigation of spintronic materials, such as magnetoresistive, spin-valve and magnetic topological insulator systems.…”