Dynamic control of field-free spin oscillator through current pulse modulation

We propose a field-free purely current driven spin oscillator device featuring a magnetic tunnel junction (MTJ) with an in-plane magnetized free and fixed layer. Our approach involves the application of a large pulse followed by a small DC current to induce spin oscillation without the need for any external magnetic field. We demonstrate that for stable sustained oscillation, the initial large pulse amplitude needs to be ~ 3× the zero-field critical current of the free layer magnet, and the smaller DC current amplitude needs to be set at ~ 0.4× the zero-field critical current. The frequency of oscillation depends primarily on the amplitude of the DC current applied. For magnets with an energy barrier between 25-80 k_BT, the device can oscillate in the microwave frequency range (6-8 GHz) with sub-mA current and power consumption in the range of few tens of microwatts.