Emission of coherent THz magnons in an antiferromagnetic insulator triggered by ultrafast spin-phonon interactions

Antiferromagnetic materials have been proposed as new types of narrowband THz spintronic devices owing to their ultrafast spin dynamics. Manipulating coherently their spin dynamics, however, remains a key challenge that is envisioned to be accomplished by spin-orbit torques or direct optical excitations. Here, we demonstrate the combined generation of broadband THz (incoherent) magnons and narrowband (coherent) magnons at 1 THz in low damping thin films of NiO/Pt. We evidence, experimentally and through modelling, two excitation processes of magnetization dynamics in NiO, an off-resonant instantaneous optical spin torque and a strain-wave-induced THz torque induced by ultrafast Pt excitatio…

Electrically tunable long-distance transport in crystalline antiferromagnetic iron oxide

Spintronics uses spins, the intrinsic angular momentum of electrons, as an alternative for the electron charge. Its long-term goal is to develop beyond-Moore, low-dissipation technology devices, recently demonstrating long-distance transport of spin signals across ferromagnetic insulators1. Antiferromagnetically ordered materials, the most common class of magnetic materials, have several crucial advantages over ferromagnetic systems2. Antiferromagnets exhibit no net magnetic moment, rendering them stable and impervious to external fields. Additionally, they can be operated at THz frequencies3. Although their properties bode well for spin transport4–7, previous indirect observations indicate…

Electrical detection of the spin reorientation transition in antiferromagnetic Tm Fe O 3 thin films by spin Hall magnetoresistance