Alexandre Abbass Hamadeh, Denys Slobodianiuk, Rayan Moukhader, Gennadiy Melkov, Vladyslav Borynskyi, Morteza Mohseni, Giovanni Finocchio, Vitaly Lomakin, Roman Verba, Grégoire de Loubens, Philipp Pirro, Olivier Klein
Current-induced self-sustained magnetization oscillations in spin-torque nano-oscillators (STNOs) are promising candidates for ultra-agile microwave sources or detectors. While usually STNOs behave as a monochromatic source, we report here clear bimodal simultaneous emission of incommensurate microwave oscillations in the frequency range of 6 to 10 gigahertz at femtowatt level power. These two tones correspond to two parametrically coupled eigenmodes with tunable splitting. The emission range is crucially sensitive to the change in hybridization of the eigenmodes of free and fixed layers, for instance, through a slight tilt of the applied magnetic field from the normal of the nanopillar...
December 15, 2023: Science Advances