Weak-value-amplification enhancement of the Magneto-optical Kerr effect in nanoscale layered structures

Abstract

The achievement of the larger Magneto-optical Kerr rotations in nanoscale layered structures is extremely important for both theoretical understandings and practical applications. In this paper, we propose a scheme for simultaneously detecting the Kerr rotation and the Kerr ellipticity based on the weak-value amplification (WVA) technique. In the Magneto-optical Kerr effect study for the layered structure, the Kerr rotation and the Kerr ellipticity are obtained by calculating the boundary matrix and the transmission matrix of the layered structure. Then, the Kerr rotation and the Kerr ellipticity can be effectively amplified as the parameters of the pre-selection in the standard weak measurement. In addition, we numerically investigate the dependence of the thickness d of Co in the nanoscale layered structure HfO2 (10~nm)/Co(d nm)/ HfO2 (30 nm)/Al(40 nm)Si films and the Co(d nm)Si films at the measurement range of 5 nm < d < 50 nm. Simulation results confirmed that the Kerr rotation and the Kerr ellipticity can be effectively amplified by choosing the appropriate post-selected state, especially when the nanoscale layered structure shows no advantage for enhancing Kerr signals over the Co(d nm)/Si films without the weak-value-amplification technique. The realization of enhancement of Kerr signals in a nanoscale layered structure may have an important application in the magneto-optic (MO) parameters measurement and the MO properties in a more complex nanoscale structure.

Tunable Quasi Bound States in the Continuum with High Q factor using Magneto-Optical Metasurface

“…The impact on metasurface caused by applied external magnetic fields tends to be relatively weak, so magnetic fields are rarely used for controlling the optical performances of conventional metasurface. However, magnetooptical metasurface provides a unique opportunity to tune optical parameters with external magnetic fields [32][33][34][35][36]. Meanwhile, the magneto-optical response of magnetic materials can be enhanced by the designed nano structures.…”