Hybrid Quantum System of Excitons and Superconductors

激子和超导体的混合量子系统

• 批准号: EP/X038556/1
• 负责人: Matthew Jones
• 金额: $ 107.17万
• 依托单位: Durham University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX038556%2F1
• 关键词: Hybrid; Quantum; System; Excitons; Superconductors

In the last 10 years, quantum computing has gone mainstream - with experiments expanding out of university research labs and into industrial R&D, led by technological giants like Google, Microsoft and IBM. Under the bonnet, many of these sophisticated machines rely on superconducting circuits to store and manipulate the quantum information. The operating frequency of these devices is similar to the clock speed of modern classical CPUs - around a few GHz. This frequency, or energy, scale is much, much smaller than that associated with room temperature, and so to get rid of thermal noise and operate in the quantum regime these devices must be cooled to a few thousandths of a degree above absolute zero. While this is possible for a single processor, it is much harder to achieve over the kilometre scales required to build a quantum network.To overcome this problem, the microwave quantum information needs to be up-converted to an optical signal that can be sent down an optical fibre, or via a satellite. The challenge is to do this efficiently without introducing additional decoherence that might destroy the fragile quantum state. Here we propose to build such a converter using Rydberg excitons - a ``quasi-particle'' with an atom-like spectrum of energy levels that exists inside a semiconducting material called cuprous oxide. Rydberg excitons provide strong coupling to optical and microwave fields and are easily prepared at the ultracold temperatures used in superconducting quantum devices. Our consortium recently became the first group to use Rydberg excitons to map a microwave signal onto light, and in this proposal, we will extend this work into the quantum regime. We will develop the methods required to physically integrate Rydberg excitons and superconducting circuits together, and study ways to maximise the coupling between them, as well as tackling the challenge of reducing optical losses in the conversion process.

在过去 10 年里，量子计算已经成为主流——实验从大学研究实验室扩展到工业研发，由谷歌、微软和 IBM 等科技巨头主导。在引擎盖下，许多复杂的机器依靠超导电路来存储和操纵量子信息。这些设备的工作频率与现代经典 CPU 的时钟速度相似 - 大约几 GHz。这种频率或能量尺度比室温小得多，因此为了消除热噪声并在量子状态下运行，这些设备必须冷却到绝对零以上千分之几度。虽然这对于单个处理器来说是可能的，但要在构建量子网络所需的千米尺度上实现要困难得多。为了克服这个问题，微波量子信息需要上转换为可以向下发送的光信号光纤，或通过卫星。挑战在于如何有效地做到这一点，而又不引入可能破坏脆弱量子态的额外退相干。在这里，我们建议使用里德伯激子构建这样一个转换器，里德伯激子是一种具有类似原子能级光谱的“准粒子”，存在于一种称为氧化亚铜的半导体材料内。里德伯激子提供与光学和微波场的强耦合，并且很容易在超导量子器件中使用的超冷温度下制备。我们的联盟最近成为第一个使用里德伯激子将微波信号映射到光上的小组，在这个提案中，我们将把这项工作扩展到量子领域。我们将开发将里德伯激子和超导电路物理集成在一起所需的方法，并研究最大化它们之间耦合的方法，以及应对减少转换过程中光学损耗的挑战。