Dresden 2017 – wissenschaftliches Programm
MA 23.2: Vortrag
Dienstag, 21. März 2017, 09:45–10:00, HSZ 403
Ultrafast magnetization dynamics triggered by intense terahertz pulses — •Julius Heitz, Tom Seifert, and Tobias Kampfrath — Fritz-Haber-Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany
We excite ferromagnetic iron thin films with sub-picosecond terahertz (THz) pulses covering the spectrum from 0.5 to 2 THz. Measurement of the magnetooptical Kerr effect (MOKE) by optical probe pulses (duration of 10 fs, center wavelength 800 nm) provides access to the time evolution of the sample magnetization. The different contributions to the magnetization dynamics are disentangled by comparing measurements with opposite THz field polarities and with different equilibrium sample magnetization. In particular, we discuss the contributions of ultrafast demagnetization and THz Zeeman torque.
The results shown here were obtained in close collaboration with the research groups of E. Beaurepaire , M. Kläui and M. Münzenberg.