Tailoring Transverse Magneto-Optical Kerr Effect Enhancement in Mie-resonant Nanowire-based Metasurfaces

Abstract: Enhancement and tailoring of the transverse magneto-optical Kerr effect (TMOKE) in hybrid metasurfaces comprising rectangular silicon nanowires coupled with a nickel substrate are demonstrated. The excitation of Mie modes of different orders in nanowires causes the enhancement. The in-plane magnetic dipole mode leads to the largest TMOKE enhancement compared to other Mie modes. Changing the width of silicon nanowires leads to a modification of that mode, thereby ensuring the tailoring of the TMOKE within the range of $2.2\% - 3.8\%$. This tunability is associated with the modification of the near-field localized at the Si/Ni interface and the far-field response of the excited magnetic dipole mode. Adjusting these two quantities allows one to achieve the highest values of the TMOKE caused by individual Mie modes in silicon nanowires.