Control of propagation characteristics of spin wave pulses via elastic and thermal effects

Abstract A study of the magnetoelastic ( ME ) and thermal effects governing the phase ( φ ) and amplitude of magnetostatic surface spin wave (MSSW) pulses propagating in Ga:YIG/GGG and permalloy magnonic waveguides is presented. The ME effects were studied in a flexural configuration, under punctual mechanical force ( F ). Thermally induced ME and demagnetization phenomena were controlled by optically injected thermal power P th . It was determined that in an unclamped Ga:YIG waveguide, the force F that induces the phase shift Δ φ =π, decreases by a quadratic law in the range from 1 m N to n N, and the P th at which Δ φ =π decreases linearly from m W to μ W as the waveguide volume decreases from mm 3 to nm 3 . For nano-volume waveguides the ME control energy ( E me ) can be of order of aJ , and the thermal control energy (Δ E th ) can be as small as 50 fJ . The response time of these effects lies in the ns time scale. Both the mechanical and the thermo-magnetic forces provide an effective control of MSSW pulse amplitude, in addition to its phase shift. The thermo-magnetic effect allows one to realize variable delays of a MSSW pulse.