Sharma Raghav, Sisodia Naveen, Iacocca Ezio, Awad Ahmad A, Åkerman Johan, Muduli P K
Department of Physics, Indian Institute of Technology, Hauz Khas, New Delhi, 110016, India.
Department of Physics, Division for Theoretical Physics, Chalmers University of Technology, 412 96, Gothenburg, Sweden.
Sci Rep. 2017 Oct 18;7(1):13422. doi: 10.1038/s41598-017-13551-5.
An important property of spin-torque nano-oscillators (STNOs) is their ability to produce a frequency modulated (FM) signal, which is very critical for communication applications. We here demonstrate a novel single sideband (SSB) modulation phenomenon using a magnetic tunnel junction (MTJ)-based STNO, which saves transmission bandwidth and in principle should minimize attenuation for wireless communication. Experimentally, lower single sidebands (LSSBs) have been successfully demonstrated over a wide range of modulation frequency, f = 150 MHz-1 GHz. The observed LSSBs are determined by the intrinsic properties of the device, which can be modeled well by a nonlinear frequency and amplitude modulation formulation and reproduced in macrospin simulations. Moreover, our macrospin simulation results show that the range of modulation current and modulation frequency for generating SSBs can be controlled by the field-like torque and biasing conditions.
自旋扭矩纳米振荡器（STNO）的一个重要特性是其产生调频（FM）信号的能力，这对于通信应用至关重要。我们在此展示了一种利用基于磁性隧道结（MTJ）的STNO的新型单边带（SSB）调制现象，该现象节省了传输带宽，并且原则上应能使无线通信的衰减最小化。在实验中，已在150 MHz至1 GHz的宽调制频率范围内成功展示了下边带（LSSB）。观察到的LSSB由器件的固有特性决定，这些特性可以通过非线性频率和幅度调制公式很好地建模，并在宏自旋模拟中重现。此外，我们的宏自旋模拟结果表明，产生SSB的调制电流范围和调制频率可以通过类场扭矩和偏置条件来控制。
