论文标题
基于收缩的旋转霍尔纳米振荡器的宽度依赖性自动振荡特性
Width dependent auto-oscillating properties of constriction based spin Hall nano-oscillators
论文作者
论文摘要
我们研究基于纳米收缩的旋转霍尔纳米振荡器（SHNOS）的当前可调微波信号特性，它是纳米收缩宽度的函数，$ W = $ 〜50--140 nm。阈值电流被发现与$ W $线性扩展，定义了恒定阈值电流密度为$ j_ {th} = $ 1.7 $ \ times $ 10 $^{8} $ a/cm $ $^2 $。尽管微波频率的当前依赖性显示出所有$ w \ geqslant $ 80 nm的相同通用非单调行为，但生成的微波信号的质量在$ W $的情况下大大提高，显示了总功率和线宽的线性$ W $依赖性。结果，140 nm纳米收缩的峰值功率大约高于80 nm纳米收缩的峰值。最小的纳米收缩，$ W = $ 50 nm，表现出不同的行为，具有更高的功率和较差的线宽，表明交叉构成了质量不同的窄构成方案。
We study the current tunable microwave signal properties of nano-constriction based spin Hall nano-oscillators (SHNOs) in oblique magnetic fields as a function of the nano-constriction width, $w=$~50--140 nm. The threshold current is found to scale linearly with $w$, defining a constant threshold current density of $J_{th}=$ 1.7 $\times$ 10$^{8}$ A/cm$^2$. While the current dependence of the microwave frequency shows the same generic non-monotonic behavior for all $w\geqslant$ 80 nm, the quality of the generated microwave signal improves strongly with $w$, showing a linear $w$ dependence for both the total power and the linewidth. As a consequence, the peak power for a 140 nm nano-constriction is about an order of magnitude higher than that of a 80 nm nano-constriction. The smallest nano-constriction, $w=$ 50 nm, exhibits a different behavior with a higher power and a worse linewidth indicating a crossover into a qualitatively different narrow-constriction regime.
