Tuning of Microwave Frequency and Power Enhancement Using Spin Torque Nano-Oscillator With Tilted Polarizer

Abstract

In this paper, we theoretically devised a spin torque nano-oscillator (STNO) with tilted polarizer (TP) with the help of two independent variables (β and θ). The spin torque induced magnetization precession dynamics is studied numerically by solving the governing Landau-Lifshitz-Gilbert-Slonczewski equation. The TP STNO free layer precession frequency is determined by varying TP angle (β) from 0° to 90°. For a particular value of β, we can vary (θ) the angle between the free layer magnetization and easy axis of magnetization from 0° to 90°. It is found that the frequency range is accessible at all tilt angles and highly tunable in the order of GHz. Also, the maximum operating frequency 124.5 GHz and corresponding power of 1.478 μW/GHz/mA <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is obtained for β = 60° and 8 = 90° with the applied current density of 10 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sup> Am <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> . Moreover, our results allow great freedom in choosing the detailed layer structure of the TP STNO and these findings pave a new route for the implementation of nanoscale microwave sources for future generation integrated electronics.