Light-induced optical orientation of magnetic moments in transition-metal doped hybrid metal halide perovskites

Using optical orientation to manipulate magnetic moments in matter with light is a key objective in opto-spintronics, however, realizations of such control on ultrafast timescales are limited. Here, we report ultrafast optical control of magnetic moment orientation in magnetically doped metal halide perovskites. Employing intense pulses of circularly polarized light, we inject populations of spin-polarized charge carriers in pristine and manganese-doped MAPbBr3 thin films. Using transient Faraday rotation spectroscopy, we probe the ultrafast magnetic moment dynamics following photoexcitation and find that light-induced magnetization in doped samples is increased by a factor of 10. We attribute this to photoexcited carriers acting on the magnetic moments of manganese dopant-ions via the sp-d exchange interaction, which forces them to align on picosecond timescales. Our findings open new avenues for device structures that use hybrid metal halide perovskites for ultrafast optical manipulation and read-out of magnetic order with the potential for high switching rates.