空穴自旋驱动机制的原位控制

空穴自旋量子比特通过电偶极自旋共振(EDSR)实现快速的全电驱动，源于其内在强自旋-轨道相互作用的两个微观机制。 Depending on how the electric field acts on the quantum dot, the spin can be driven either by a modulation of its g-factor or by a displacement of the wavefunction. Here, we demonstrate in-situ control over the dominant EDSR driving mechanism of a hole-spin qubit in a silicon fin field-effect transistor by applying microwave signals to two different gate electrodes, thereby tuning the orientation of the local electric field. We measure the effective g-factor, its electrical tunability, and the Rabi frequency as functions of magnetic-field orientation. Their distinct angular dependencies, analyzed using a g-matrix formalism, allow us to identify the underlying driving processes and track their relative contributions for different drive configurations. By selecting the drive electrode, we can switch from a regime dominated by g-factor modulation to one with a strong contribution from wavefunction displacement. This in-situ tunability provides direct experimental access to both spin-driving mechanisms and offers a route toward optimized spin-qubit performance. 我们通过将微波信号施加于两个不同的栅极电极来调节局部电场的取向，从而在硅fin场效应晶体管中的空穴自旋量子比特上实现对主导EDSR驱动机制的原位控制。 我们测量了有效g因子、其电可调性以及随磁场取向变化的拉比频率。 通过g矩阵形式化方法分析其不同的角度依赖性，使我们能够识别潜在的驱动过程并跟踪不同驱动配置下其相对贡献。 通过选择驱动电极，我们可以从g因子调制主导的 regime切换到波函数位移贡献占主导的 regime。 这种原位可调性提供了对两种自旋驱动机制的直接实验性访问，并为实现优化的自旋量子比特性能提供了途径。