An oscillator is provided including a nanopillar and current injector for injecting a power supply current through the nanopillar, the nanopillar including at least one pattern including first and second layers made from a ferromagnetic material separated from each other by an intermediate layer made from a non-magnetic material. Each of the first and second ferromagnetic layers is prepared such that its remanent magnetic configuration corresponds to a vortex configuration and the polarity of the vortex core of the first layer is opposite the polarity of the vortex core of the second layer. The intermediate layer can allow repellant magnetic coupling between the two vortices of the first and second layers, for a zero intensity of the power supply current and a zero amplitude of the outside magnetic field.