Executive Summary : | Magnonics is a promising field of energy-efficient devices that uses spinwaves, the counterpart of magnon, to carry and process information in the microwave regime. The artificial spin-ice (ASI) system is rich in fundamental physics and can be used for reconfigurable magnonic devices through band structure engineering. To use ASIs in re-programmable magnonic devices, unidirectional propagation of spin waves is essential, which can be achieved by altering the non-reciprocity factor. The main drawback for spinwave propagation is the material's damping, which can be modified by injecting spin current into the ferromagnetic layer via spin-orbit torque. The spin orbit torque has two parts: damping-like torque, acting as an effective damping, and field-like torque, acting as an effective field. S. Saha et al. showed that the modification of damping depends on the direction of the damping-like and field-like torques. At a certain angle, the damping-like torque will dominate and compensate for the intrinsic damping of the material, allowing the spinwave to propagate longer distance without damping. Once damping is controlled, the spinwave will be excited at one end of the spin ice structure using a microwave antenna marked, and the transmitted spin wave will be detected at another end. This project aims to demonstrate spinwave non reciprocity for connected ASI systems and control damping by changing the relative direction of spin polarization and the precessional axis of magnetization. This will open up novel possibilities for low-power re-programmable magnonic devices based on the artificial spin-ice system. |