Electrically induced strong modulation of magnon transport in ultrathin magnetic insulator films

Magnon transport through a magnetic insulator can be controlled by current-biased heavy-metal gates that modulate the magnon conductivity via density. Here, we report nonlinear modulation effects in 10$\,$nm thick yttrium iron garnet (YIG) films. The efficiency is larger than 40\%/mA. spin signal at high DC current density (2.2$\times 10^{11}\,$A/m$^{2}$) saturates for 400$\,$nm wide Pt gate, which indicates even levels instability cannot reached spite of quality