论文标题
Si/SigE异质结构中的自旋轨道增强，振荡GE浓度
Spin-orbit enhancement in Si/SiGe heterostructures with oscillating Ge concentration
论文作者
论文摘要
我们表明，Si/Sige异质结构的量子井区域内的GE浓度振荡可以显着增强低能传导带谷的自旋轨道耦合。具体而言，我们发现，对于$λ= 1.57〜 \ text {nm} $，平均$ \ bar {n} _ {n} _ {\ text {ge}} = 5 \％$在量子井区域中，dresselhaus spin-spin-orbit a在物理上，在所有物理上，在所有物理上均更大的阶段，在没有GE浓度振荡的常规SI/SIGE异质结构中发现。这种增强是由GE浓度振荡产生的波连接卫星峰值$2π/λ$在每个山谷的动量空间中的距离，然后通过Dresselhaus旋转轨道耦合将其融入对面的山谷。我们的结果表明，增强的自旋轨道耦合可以在没有微磁体的情况下使用电偶极旋转谐振在Si量子点内快速自旋操作。实际上，我们的计算产生了一个Rabi频率$ω_ {\ text {rabi}}/b> 500〜 \ text {mhz/t} $附近的最佳ge振荡波长$λ= 1.57〜 \ text {nm} $。
We show that Ge concentration oscillations within the quantum well region of a Si/SiGe heterostructure can significantly enhance the spin-orbit coupling of the low-energy conduction-band valleys. Specifically, we find that for Ge oscillation wavelengths near $λ= 1.57~\text{nm}$ with an average Ge concentration of $\bar{n}_{\text{Ge}} = 5\%$ in the quantum well region, a Dresselhaus spin-orbit coupling is induced, at all physically relevant electric field strengths, which is over an order of magnitude larger than what is found in conventional Si/SiGe heterostructures without Ge concentration oscillations. This enhancement is caused by the Ge concentration oscillations producing wave-function satellite peaks a distance $2 π/λ$ away in momentum space from each valley, which then couple to the opposite valley through Dresselhaus spin-orbit coupling. Our results indicate that the enhanced spin-orbit coupling can enable fast spin manipulation within Si quantum dots using electric dipole spin resonance in the absence of micromagnets. Indeed, our calculations yield a Rabi frequency $Ω_{\text{Rabi}}/B > 500~\text{MHz/T}$ near the optimal Ge oscillation wavelength $λ= 1.57~\text{nm}$.
