Mizokuchi Raisei, Bugu Sinan, Hirayama Masaru, Yoneda Jun, Kodera Tetsuo
Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, Meguro, Tokyo, 152-8552, Japan.
Tokyo Tech Academy for Super Smart Society, Tokyo Institute of Technology, Meguro, Tokyo, 152-8552, Japan.
Sci Rep. 2021 Mar 12;11(1):5863. doi: 10.1038/s41598-021-85231-4.
Radio-frequency reflectometry techniques are instrumental for spin qubit readout in semiconductor quantum dots. However, a large phase response is difficult to achieve in practice. In this work, we report radio-frequency single electron transistors using physically defined quantum dots in silicon-on-insulator. We study quantum dots which do not have the top gate structure considered to hinder radio frequency reflectometry measurements using physically defined quantum dots. Based on the model which properly takes into account the parasitic components, we precisely determine the gate-dependent device admittance. Clear Coulomb peaks are observed in the amplitude and the phase of the reflection coefficient, with a remarkably large phase signal of ∼45°. Electrical circuit analysis indicates that it can be attributed to a good impedance matching and a detuning from the resonance frequency. We anticipate that our results will be useful in designing and simulating reflectometry circuits to optimize qubit readout sensitivity and speed.
射频反射测量技术对半导体量子点中的自旋量子比特读出至关重要。然而，在实际中很难实现大的相位响应。在这项工作中，我们报告了在绝缘体上硅中使用物理定义量子点的射频单电子晶体管。我们研究了那些没有被认为会阻碍使用物理定义量子点进行射频反射测量的顶栅结构的量子点。基于适当考虑了寄生元件的模型，我们精确地确定了栅极依赖的器件导纳。在反射系数的幅度和相位中观察到清晰的库仑峰，具有约45°的显著大的相位信号。电路分析表明，这可归因于良好的阻抗匹配和与共振频率的失谐。我们预计我们的结果将有助于设计和模拟反射测量电路，以优化量子比特读出灵敏度和速度。
