提出一种新型的电流驱动对称磁多层结构纳米自旋传输矩微波振荡器结构。由两个铁磁膜组成,具有相同厚度,中间被一薄的非磁层隔开。纳米磁多层柱的上、下都有金属层作为电极。一个恒定不变的直流电流垂直通过该磁多层结构时,产生自旋极化和自旋传输矩,并施加自旋矩于每一磁层。当电流超过临界值时,引起两个磁膜的磁化矢量交替翻转方向,并导致磁多层电阻的周期性变化,从而产生稳定的微波振荡。振荡频率与电流呈线性关系,变化范围1~100GHz。微波功率也可以用电流调节,范围在1μW~1mW。
A novel structure of the spin transfer torque nano-oscillator with symmetrical magnetic multilayers was presented. It consisted of two ferromagnetic films with the same thickness separated by a thin non-magnetic film. There were two metal electrodes at the top and bottom of the magnetic multilayers. When the current passed vertically through the magnetic multilayers, the spin polarization and spin transfer torque were generated, and spin transfer torque would affect the magnetization of each free layer. When the current exceeded the critical value, the magnetization vector directions of both magnetic films were alternately switched without external magnetic field. The resistance of the magnetic multilayers was periodically changed, and the steady microwave oscillation was generated. There is a line relationship between the oscillation frequency and the current at 1 - 100 GHz. The microwave power can be modulated by the current, and the range is 1 μW- 1 mW,