Spintronics II: magnonics, rf dynamics and ultrafast spintronics

Nano-oscillators for rf spintronics
Spintronic nano-oscillators (STNO) based on the spin-transfer dynamics of a magnetic vortex are model systems on which we have been working for over 15 years. Understanding their spin-transfer dynamic behavior and their detection and/or emission properties in the radiofrequency range enables us to study complex dynamic regimes of strongly coupled nano-oscillators, aiming at developing ultra-sensitive sensors or optimizing their performance as rf energy harvesters or wake-up receivers.

Spintronics at interfaces: radiation emission from visible to THz
The conversion of spin-polarized current into radiation (visible or THz) offers new opportunities for information coding. Two distinct aspects are addressed in this research operation: emission/absorption in the visible, and emission in the THz spectral range.
In the visible, one of the goal is to extend the result from the spin light emission diode (LED) to Vertical-External-Cavity Surface-Emitting Laser (VECSEL). In the terahertz range, shining femtosecond laser pulses on bilayers made of a magnetic material and of an active spin-orbit layer results in a large and broadband THz (1-30 THz) emission. The light absorption lead to an ultrafast demagnetization process and the generation of spin-polarized hot carriers. The associated ultra-fast spin-current can efficiently be converted in a lateral THz charge current through bulk inverse spin-Hall effects (ISHE) in materials like heavy metals (Pt, W or Ta), and/or directly at the interface through inverse Rashba-Edelstein effects (IREE) in presence of polarized surface states like in topological insulators (Bi1-xSbx ,Bi2Se3 ,..). Such fundamental physical processes are at the origin of several novel concepts of spin-based THz spintronic devices.