Exploiting nonlinear oscillators for quantum information processing and measurement

该项目的主要目标是开发克尔参数振荡器(KPO)。这些KPO将首先用于产生巡回猫态，进一步的目标是观察跨越量子经典边界的混沌行为，实现两个KPO门，并使用KPO实现量子模拟。几代KPO已经被设计、制造和实验表征。第一代人遭受着高损失率的痛苦，使得前面提到的大多数实验目标都无法实现。该装置每一代都在改进，最新的一代具有可能允许对所提到的一些实验进行原理验证的特性。此外，我们还知道如何进一步提高器件的特性，为以后的实验做准备。这个项目还没有公布结果，对未来的结果很有希望。除了主要项目外，我还与Axion搜索团队合作开发了约瑟夫森参数放大器。这些放大器将使它们能够在比仅使用传统HEMT放大器更短的时间内显示或排除轴子的存在。这些放大器经过测试工作正常，目前正在该项目中使用。到目前为止，我们已经就这个主题共同撰写了2篇论文。我还与S·河野合作开发了约瑟夫森量子过滤器，旨在打破快速控制量子比特和由于控制线的存在而导致该量子比特衰减之间的权衡。

The main goal of the project was to develop Kerr Parametric Oscillators (KPOs). These KPOs were to be used first to generate itinerant cat states, with further goals being observation of chaotic behaviour across the quantum-classical boundary, implementing two-KPO gates, and moving towards implementations of quantum simulations using KPOs.Several generations of KPOs have been designed, fabricated, and experimentally characterized. The first generations suffered from high loss rates, rendering most of the mentioned experimental goals impossible. The device was improved each generation, and the most recent generation has properties that may allow proof-of-principle demonstrations of some of the mentioned experiments. Moreover, we know how to further improve the device characteristics for future experiments. This project has not yet lead to published results, is promising regarding future results.Besides the main project, I developed Josephson parametric amplifiers for a collaboration with an axion search team. These amplifiers will allow them to show or exclude the existence of axions in a much shorter timescale than would be possible using only conventional HEMT amplifiers. The amplifiers were tested to work, and are in current use within that project. We have so far co-authored 2 papers on this subject.I also collaborated with S. Kono on his project on developing a Josephson Quantum Filter, aiming to break the trade-off between fast control of a qubit, and the decay of that qubit due to the presence of the control line.