Frequency and power enhanced Magneto Resistance-based Tilted Polarizer Spin Torque Nano-Oscillator

Abstract

We have theoretically devised the Magneto Resistance (MR)-based Tilted Polarizer Spin Torque Nano-Oscillator (TP STNO) with homogeneous and heterogeneous spin valve structure by varying the Tilted Pinned Layer (TPL) (\(\beta\)) and (\(\theta\)), an angle between the free layer magnetization, and the free layer easy axis of the device. Here, we have included the resistance of the device via current and studied how it affects the frequency and its tunability with power. In this article, we have numerically investigated the magnetization precession dynamics led by the Spin Transfer Torque (STT) phenomena by solving the famous Landau–Lifshitz–Gilbert–Slonczewski (LLGS) equation. By varying TPL angle (\(\beta\)) in MR-TP STNO from \(0^{\circ }\) to \(90^{\circ }\), the free layer precessional dynamics of the device is studied. For all the tilt angles, the frequency range is accessible as well as highly tunable in GHz regime for both the homo- and heterogeneous devices. As far as the homogeneous device is concerned, the maximum frequency of about 24.75 GHz with the corresponding power of about 1.122 (\(\mu \mathrm{W}/\mathrm{mA}^2\))/GHz for \(\beta = 60^{\circ }\) and \(\theta = 90^{\circ }\) is obtained which is low when compared with the authors previous work [17] because of the inclusion of resistance into the device. For same \(\beta\) and \(\theta\), the maximum operating frequency of about 202.3 GHz and its corresponding power of about 2.426 (\(\mu \mathrm{W}/\mathrm{mA}^2\))/GHz are obtained for the heterogeneous device where the resistance of the device is low as compared to homogeneous device. From the reported results, it is evident that the device based on heterogeneous emits more frequency and power than the homogeneous device. The obtained results are highly alluring paves a smart way for the implementation of microwave nano-scale sources for the foreseeable spintronic devices.