Femtosecond generation and propagation of spin currents in magnetic heterostructures

When a magnetic multilayer absorbs a strong femtosecond laser pulse, it triggers both ultrafast demagnetization and the generation of hot electrons. These processes can produce a spin current capable of manipulating magnetic states—such as reversing layer magnetization or driving magnetic textures like domain walls [1,2]. While our recent experiments have successfully demonstrated magnetization reversal via such spin currents [3–5], the underlying mechanisms—including ultrafast demagnetization, spin-dependent transport, spin transfer torque (STT), and heat dissipation—remain complex and not yet fully understood. This PhD project focuses on developing efficient methods for generating and propagating spin currents on femtosecond timescales across diverse magnetic heterostructures. This approach will allow us 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. The project builds on a long-standing collaboration between two world leading groups in this area, the Physics of Nanostructures group at Eindhoven University of Technology (TU/e) and the Spin group at Institut Jean Lamour (UL-CNRS). The project will leverage state-of-the-art optical and growth techniques as well as the complementary expertise of both teams. This collaboration will thus allow us to tackle complex fundamental and technical challenges in the exploration and application of ultrafast spin currents. We are convinced that the novel and disruptive idea of using laser induced spin currents in an application perspective will allow us to move toward more environment friendly digital technologies. The selected PhD student will investigate and evaluate the efficiency of the generation of the pure spin currents following laser induced ultrafast demagnetization, their propagation and their interaction with another magnetic material in a number of systems. The student will work on state-of-the-art time resolved magneto-optical setups and they will extensively learn about spintronics, magnetism and ultrafast optics. See attached PDF for more details.