Investigating Coherent Magnetization Control with Ultrashort THz Pulses

Applied Sciences

Ekaterina Zapolnova¹  Nikola Stojanovic¹  Torsten Golz¹  Rui Pan¹  Grégory Malinowski²  Gheorghe Sorin Chiuzbaian³  Emmanuelle Jal³  Boris Vodungbo³  Xuan Liu³  Romain Jarrier³  Renaud Delaunay³  Jan Lüning³ 

[1] Deutsches Elektronen-Synchrotron, 22607 Hamburg, Germany;Institut Jean Lamour (UMR 7198), Université de Lorraine, Centre National de la Recherche Scientifique (CNRS), 54011 Nancy, France;Laboratoire de Chimie Physique-Matière et Rayonnement (LPCMR), Sorbonne Université, Centre National de la Recherche Scientifique (CNRS), 75252 Paris, France;

关键词: X-ray free electrons laser;    ultrafast demagnetization;    terahertz radiations;   

DOI  :  10.3390/app12031323

来源: DOAJ

【 摘 要 】

Coherent terahertz control of magnetization dynamics is an area of current interest due to its great potential for the realization of magnetization control on ultrafast timescales in commercial devices. Here we report on an experiment realized at the THz beamline of the free electron laser FLASH at DESY which offers a tunable terahertz radiation source and spontaneously synchronized free-electron laser X-ray pulses to resonantly probe the magnetization state of a ferromagnetic film. In this proof-of-principle experiment, we have excited a thin Permalloy film at different THz wavelengths and recorded the induced magnetization dynamics with photons resonantly tuned to the Ni $M_{2,3}$ absorption edge. For THz pump pulses including higher orders of the undulator source we observed demagnetization dynamics, which precise shape depended on the employed fundamental wavelength of the undulator source. Analyzing the shape in detail, we can reconstruct the temporal profile of the electric field of the THz pump pulse. This offers a new method for the realization of an in-situ terahertz beamline diagnostic which will help researchers to adjust the pulse characteristics as needed, for example, for future studies of THz induced coherent control of magnetization dynamics.

【 授权许可】

Unknown