Monitoring laser-induced magnetization in FeRh by transient terahertz emission spectroscopy
Nilesh Awari, Anna Semisalova, Jan‐Christoph Deinert, K. Lenz, J. Lindner, Eric E. Fullerton, Vojtěch Uhlíř, Jingtao Li, B. M. Clemens, Robert Carley, A. Scherz, Sergey Kovalev, Michael Gensch
Abstract
In this study, a conceptually different approach for investigating magnetic phase transitions in ultra-thin films is presented. THz emission from a laser-excited material is used to monitor the magnetization dynamics during the laser-driven antiferromagnetic to ferromagnetic transition in FeRh. The emitted THz signal is calibrated against static magnetometry data measurements, giving a direct measure of the absolute magnetic moment of the sample on the sub-picosecond timescale. The technique is, therefore, highly complementary to conventional time-resolved experiments such as time resolved magneto-optic Kerr effect (MOKE) or x-ray magnetic circular dichroism.