Due to its importance in future spintronic-based memory devices, the Dzyaloshinskii–Moriya interaction (DMI) has been under intense investigation recently. Yet the feasibility of developing straightforward DMI measurement methods, especially using quasi-static tools, is debatable. Here, we present the observation of a shifted, asymmetric magnetization reversal manifested by interfacial DMI (iDMI) via magnetoresistance (MR) measurements for the first time. A shifted asymmetric MR response results from iDMI in an ultrathin symmetric unpatterned [Ni80Fe20/Pt] ×10 multilayer stack. Moreover, to reveal the presence of iDMI, we have experimentally seen iDMI from nonreciprocity in spin-wave dispersion using Brillouin light-scattering. Also, as a previously developed quasi-static method, we compare the MR results with the magneto-optical Kerr effect with the observed MR results. Our findings open pathways towards direct observation of iDMI in magnetic multilayers.

Attempt to manufacture photonics devices on silicon requires theoretical and numerical prediction. This essay presents Compound FDTD (C-FDTD) method for comprehensive simulation of silicon photonics devices. Although this method is comprehensive, it maintains conventional Yee algorithm. The method involves variation of refractive index due to nonlinear effects. With the help of this simulator, refractive index change due to free-carriers created through two photon absorption and Kerr effect in silicon waveguide is considered. Results indicate how to choose pump pulse shape to optimum operation of active photonics devices. Also conductivity variation of Si waveguide due to change in free-carrier density is studied. By considering variations in conductivity profile, we are able to design better schemes for sweep free carriers away with reverse bias or nonlinear photovoltaic effect for fast devices and Raman amplifiers