Charge and spin nonlocal interaction in SiGe hybrid cQED architecture

在2015财年，主要工作是致力于器件制造的开发。在制造量子点的过程中遇到的困难。然而，超导谐振器的制造和表征按计划进行。我们成功地实现了质量因子约为30000的谐振器，这比GaAs中实现的谐振器大一个数量级，证明了使用SiGe作为混合cQED结构的二维气体异质结构的优势之一。作为副业，我们详细研究了宿主材料的核自旋动力学对GaAs（含100%核自旋）中电子自旋在短时间尺度上的失相的影响。这项工作对当前的项目具有重要意义：当我们将SiGe中的电子自旋（与4.8%的核自旋相互作用）与光子耦合时，典型的相互作用时间尺度将更短，导致比预期更长的相干时间，并开启在更短时间尺度上研究核自旋动力学的可能性。

in the fiscal year FY2015, the main workload was devoted to the development of the device fabrication. Difficulties where unfortunately encountered in the fabrication of the quantum dots. However, the fabrication and characterization of the superconducting resonators went as planned. We succeeded in realizing resonators with quality factors of around 30000, which is one order of magnitude larger than the one realized in GaAs, demonstrating one of the advantages of using SiGe as a two-dimensional gas heterostructure for our hybrid cQED architecture. As a side work, we studied in detail the the influence of the dynamics of the nuclear spins of the host material on the dephasing of an electronic spin in GaAs (containing 100% of nuclear spins) on short time scales. This work has important implications for the current project : when we will couple an electronic spin in SiGe (interacting with 4.8% of nuclear spins) to photons, the typical interaction time scale will be even shorter, leading to longer coherence times than anticipated and opening the possibility to study the nuclear spins dynamics on even shorter time scales.