Spin-orbit torque nano-oscillators based on bilayers of ferromagnetic and nonmagnetic metals are ultra-compact current-controlled microwave signal sources. They are attractive for practical applications such as microwave assisted magnetic recording, neuromorphic computing, and chip-to-chip wireless communications. However, a major drawback of these devices is low output microwave power arising from the relatively small anisotropic magnetoresistance of the ferromagnetic layer. Here we experimentally show that the output power of a spin-orbit torque nano-oscillator can be significantly enhanced without compromising its structural simplicity. Addition of a ferromagnetic reference layer to the oscillator allows us to employ current-in-plane giant magnetoresistance to boost the output power of the device. This enhancement of the output power is a result of both large magnitude of giant magnetoresistance compared to that of anisotropic magnetoresistance and their different angular dependencies. Our results hold promise for practical applications of spin-orbit torque nano-oscillators.

基于铁磁性和非磁性金属双层的自旋轨道扭矩纳米振荡器是超紧凑的电流控制微波信号源。它们对于诸如微波辅助磁记录，神经形态计算和芯片间无线通信等实际​​应用具有吸引力。然而，这些设备的主要缺点是由于铁磁层的相对较小的各向异性磁阻而产生的低输出微波功率。在这里，我们通过实验表明，自旋轨道扭矩纳米振荡器的输出功率可以显着提高，而不会损害其结构简单性。在振荡器上增加铁磁参考层，使我们能够利用面内电流巨磁阻来提高器件的输出功率。输出功率的这种提高是由于与各向异性磁阻相比具有较大的巨磁阻以及不同的角度依赖性。我们的结果为自旋轨道扭矩纳米振荡器的实际应用提供了希望。