Nanometer-wavelength magnon manipulation via terahertz spin and orbital currents in magnetic heterostructures (TMAG)

• Applicants: Dr. Sergey Kovalev; Dr. Ruslan Salikhov
• Subject Area: Experimental Condensed Matter Physics
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 566522216

The increasing demand for high-speed communications and data processing has prompted exploration into novel concepts in the terahertz (THz) frequency regime, particularly in THz spintronics/orbitronics and magnonics. The aim of this project is to investigate mechanisms for achieving energy-efficient high-speed communication and logic units, focusing on THz-driven magnonic phenomena and ultrafast orbital currents. Specifically, the study delves into THz spin wave generation via orbital torque in oxidized metal/ferromagnet (OM/FM) heterostructures, aiming to understand the efficiency of THz orbital torque in coupling THz light with nanometer-wavelength spin waves. Experimental investigations probe the characteristics of the orbital torque effect at OM/FM interfaces on picosecond timescales. Furthermore, the research examines THz magnon-generated ultrafast spin and orbital currents, with a particular focus on the inverse orbital Rashba-Edelstein effect in OM/FM heterostructures. This objective aims to verify the efficiency of orbital-to-charge conversion on a picosecond timescale, utilizing orbital pumping from THz ferromagnetic resonance and THz time-domain spectroscopy as a detection unit. Additionally, the study endeavors to elucidate the interactions between THz spin waves in complex heterostructures, exploring spin(orbital) torque-induced coherent excitations in magnetic multilayers. Through the exploration of novel pathways for ultrafast and coherent excitation of orbital currents, alongside the efficient generation, detection, and manipulation of high-energy spin waves on a picosecond timescale, our study endeavors to make a significant contribution to the field of THz orbitronics and magnonics. Consequently, this research project aims to advance the potential applications of nanometer-wavelength spin waves and THz magnonic crystals as media for high-speed communication and logic units.

• DFG Programme: Research Grants