Microwave quantum optics with tunable cavity resonators and superconducting qubits

具有可调谐腔谐振器和超导量子位的微波量子光学

基本信息

批准号：
20F20757
负责人：
中村泰信
金额：
$ 1.41万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for JSPS Fellows
财政年份：
2020
资助国家：
日本
起止时间：
2020-07-29 至 2023-03-31
项目状态：
已结题

项目摘要

Throughout this work, we have developed a versatile CAD-assisted circuit design platform and performance estimation tools for designing JTWPAs in different variants, which can reproduce the results of implemented JTWPAs in literatures.In fabrication, we have been searching for the most suitable Josephson junction design to achieve a high homogeneity in Josephson junction parameters. From the beginning to end of the work, we have reduced the standard deviation (stdev) in junction resistance from over 20% down to 4% in our last measured sample, covering a chip area sufficient for implementing JTWPAs. Our latest junction design to be used in the next batch of JTWPA samples will further reduce the stdev to around 1%, while also greatly improving the junction yield over the previous designs.From our sample measurements, we have successfully fabricated a low-loss nonlinear transmission line which could act as the basis for JTWPAs. With a comparable electrical length and number of unit cells to JTWPAs in literatures (1413 cells in our sample, comparing to 1000-2000 cells in literatures), we have achieved < 1dB insertion loss comparing to typically 3-6 dB in most other implementations over a similar frequency range. The preliminary measurement results of our samples demonstrated a gain up to an average of 7.5 dB, over a wide bandwidth of 6 GHz. We expect future devices to catch up in terms of gain with more optimized junction and circuit designs.

在整个工作中，我们已经开发了一个多功能的CAD辅助电路设计平台和用于设计不同变体中JTWPA的性能估算工具，该工具可以重现文学中实现的JTWPA的结果。在制造中，我们一直在寻找最合适的Josephson Junction Design，以实现Josephson Josephson结合参数的高质量。从工作的开始到结尾，我们将连接阻力的标准偏差（STDEV）从上次测量的样品中的20％降低到4％，涵盖了足以实施JTWPA的芯片区域。我们在下一批JTWPA样品中使用的最新连接设计将进一步将STDEV降低到1％左右，同时也大大提高了与先前设计相比的连接产量。从我们的样品测量值中，我们已经成功地制造了一条低损失的非线性传输线，可以用作JTWPA的基础。在文献中，与JTWPA相当（样品中的1413个细胞，与文献中的1000-2000个细胞相比）具有可比的电细胞数量和数量，我们在大多数其他实现范围内实现了<1dB的插入损失。我们样品的初步测量结果表明，在6 GHz的宽带宽度上，平均增益高达7.5 dB。我们希望将来的设备通过更优化的连接和电路设计来赶上增益。