Ultrafast Modulation of Polarization in Spintronic THz Emitters Enhanced by Field Induced Spin Reorientation Transition

We demonstrate an efficient and simple modulation of the polarization in Spin-tronic Terahertz Emitters, by rapid switching of the magnetization using high-frequency magnetic field, enhanced by field induced Spin Reorientation Transition (SRT). The instability of the magnetic layer at the transition allows for a higher sensitivity of the magne-tization and an efficient switching at lower power of the polarization at frequencies up to 100kHz.