Abstract:

This talk explores the development and application of advanced optical detection techniques to study ultra-small polarization changes in spin systems. We introduce the principles of quantum weak values and their practical applications in magneto-optic and spintronic effects. Our research focuses on leveraging weak value amplification to design the spin Hall effect of light-based magneto-optic Kerr effect (SHEL-MOKE) setup for detecting magnetic signatures in 2D materials. A chemical vapor deposition technique was optimized to produce high quality atomic layers of molybdenum disulphide (MoS2) with engineered control over flake geometry. Novel hysteresis like response from MoS2 monolayer has been observed using SHEL-MOKE, surpassing conventional electrical detection methods. Additionally, we delve into spin-based phenomena, including the spin Hall effect and spin-Hall induced spin-transfer torque, with investigations into synthetic antiferromagnetic and ferromagnetic systems as potential switching devices driven by spin angular momentum transfer. Using time-resolved magneto-optic Kerr effect (TR-MOKE), we achieve high-precision imaging and optical ferromagnetic resonance spectroscopy of these spin dynamical nanostructures. We highlight the potential of quantum weak value measurements and TR-MOKE to enhance our understanding of magneto-optic and spintronic phenomena, and materials science.