论文标题
在合成旋转轨道场中硅自旋量子置量宽松的理论
Theory of Silicon Spin Qubit Relaxation in a Synthetic Spin-Orbit Field
论文作者
论文摘要
在存在磁场梯度的情况下，我们发展了单电子硅自旋量子误位弛豫的理论。这种现场梯度通常由片上的微型磁体生成，以允许自旋Qubits上的电量子门。我们建立在山谷依赖的包膜函数理论的基础上，该理论能够在界面上具有任意粗糙度的硅量子点中对电子波函数的分析。我们假设在Si/Sige界面上存在单层原子步骤，并研究梯度场的存在如何修饰旋转混合机制。我们表明，我们的理论建模可以在存在微型磁铁的情况下定量地重现硅中量子弛豫的实验测量结果。我们进一步研究了场梯度如何修改硅自旋量子的EDSR RABI频率。尽管这在很大程度上取决于界面粗糙度的细节，但有趣的是，我们发现在带有理想界面的自旋量子置量轴上添加一个Micromagnet甚至可以在外部磁场强度的一定间隔内降低EDSR频率。
We develop the theory of single-electron silicon spin qubit relaxation in the presence of a magnetic field gradient. Such field gradients are routinely generated by on-chip micromagnets to allow for electrically controlled quantum gates on spin qubits. We build on a valley-dependent envelope function theory that enables the analysis of the electron wave function in a silicon quantum dot with an arbitrary roughness at the interface. We assume the presence of single-layer atomic steps at a Si/SiGe interface and study how the presence of a gradient field modifies the spin-mixing mechanisms. We show that our theoretical modeling can quantitatively reproduce results of experimental measurements of qubit relaxation in silicon in the presence of a micromagnet. We further study in detail how a field gradient can modify the EDSR Rabi frequency of a silicon spin qubit. While this strongly depends on the details of the interface roughness, interestingly, we find that adding a micromagnet on top of a spin qubit with an ideal interface can even reduce the EDSR frequency within some interval of the external magnetic field strength.
