2023 - SLAM (Manipulation de l'aimantation par impulsion d'électron et de photon sub-picoseconde)

Today, the digital world is growing exponentially. On one hand digitalization can help find solutions against global warming and for more sustainable technologies but, on the other hand, more and more electronic devices (sensors, transducers, processors, memory, logics) causes more energy consumption and an increased demand for rare and critical materials. We are convinced that only new and disruptive approaches will allow us to move toward more environment friendly digital technologies. In this context, ultrafast manipulation of spins in a controlled manner is a milestone of solid-state physics. The motivation is to enable ultra-fast and energy efficient storing, writing and reading of binary data. Here we propose to develop and understand ultrafast spintronics devices, which combine the ideas and concepts of magneto-optics and opto-magnetism with spin transport phenomena, supplemented with the possibilities offered by photonics for ultrafast low-dissipative manipulation and transport of information. In the last few months the partner (IJL- France) has demonstrated in a spintronic device (a spin valve) that one single femto-second laser pulse could deterministically reverse the magnetization of a ferromagnetic layer in only a few hundreds of femtoseconds (...)

The major objectives of our project are:
 * Improve our understanding of femtosecond light pulses to ultrashort polarized and unpolarized current pulse conversion by characterizing spin current pulses emitted by different magnetic materials (thickness, saturation magnetization, Curie temperature etc.) in response to various laser pulses excitations (fluence, duration, photon energy and polarization) and by comparing the measured and calculated results.
 * Unravel the mechanisms regulating the propagation of the spin-polarized electron pulse through the non-magnetic spacer and their transmission/reflection at the interfaces between this spacer and the surrounding magnetic layers.
 * Improve our understanding of the interaction between ultrashort spin current pulses and magnetizations