Speaker
Description
Since the first demonstration of the possibility of manipulating the magnetization using femtosecond (fs) laser pulses performed by Beaurepaire et al. in 1996 [1], time-resolved pump-probe measurements based on the magneto-optical Kerr or Faraday effects have provided an invaluable tool for the study of ultrafast magnetic dynamics in many relevant systems [2]. Although rapid advances in ultrafast optical methods have allowed the temporal resolution to be gradually improved, the measurements are routinely performed with few tens of fs (e.g., 30-50 fs). Therefore, achieving a higher temporal resolution is very important for studying ultrafast processes in matter, such as the spin-orbit coupling, the exchange interaction, the structural anisotropy of the materials, among others. With this in mind, we have developed a unique compact versatile time-resolved magneto-optical (TR-MO) system to study ultrafast magneto dynamics processes. Our setup uses state-of-the-art ultrafast optical methods to deliver ultrashort laser pump and probe sub-5-fs carrier-envelope phase (CEP) stabilized pulses at the sample position, permitting the observation of ultrafast magnetization dynamics at unprecedented optical temporal resolutions. This few-cycle regime is also highly promising for the direct excitation and observation of coherent ultrafast magneto dynamic behaviour [3]. Using our TR-MO system we performed magnetization dynamics measurements of [CoFeB/Pd] multilayer thin films in different temporal regimes, as precessional motion [4] and ultrafast demagnetization (Fig.1).
