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

TL;DR

This study demonstrates ultrafast optical control of magnetic moments in manganese-doped metal halide perovskites using circularly polarized light, revealing a tenfold increase in magnetization and potential for high-speed opto-spintronics devices.

Contribution

It introduces a method for ultrafast optical manipulation of magnetic moments in hybrid perovskites, showing significant enhancement of magnetization via light-induced spin polarization.

Findings

Light increases magnetization by a factor of 10 in doped samples.

Magnetic moments align on picosecond timescales due to photoexcited carriers.

Potential for high-speed magnetic switching in perovskite-based devices.

Abstract

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.