| 研究実績の概要 |
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.
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