Title: "Nonlinear Spintronics: Unveiling Quantum Rectenna for Sensing and Energy Applications"

Speaker: Dr. Dushyant Kumar, Netaji Subhas University of Technology, India

Abstract: Any second-order nonlinearity such as nonlinear magnetoresistance, or nonlinear Hall effect (NLHE) exhibits two components; one is the voltage oscillating at twice the frequency 2ω of the driving alternating current and the other is the d.c. component that is generated due to the rectification effect. Therefore, nonlinear spintronics can be utilized in applications requiring frequency doubling or rectification such as energy harvesting, wireless communications, and terahertz detection. In particular, the Quantum Nonlinear Hall Effect (QNHE), which can produce a transverse voltage without any magnetic field, is a potential alternative for energy harvesting. In my recent first-author publication in Nature Nanotechnology, we have, for the first time, reported the room temperature nonlinear Hall effect in a Weyl semimetal. We went ahead and exploited this effect to demonstrate wireless RF rectification with zero external bias and magnetic field. This work opens a door to realizing room temperature Quantum Rectenna which can be utilized in sensing and energy applications. During my presentation, I will discuss this work in detail followed by the recent work in this direction and direct optical visualization of the spin texture in topological materials and its utilization for field-free switching of magnetization in SOT-MRAM.