A Hybrid Atom-Photon-Superconductor Quantum Interface

混合原子-光子-超导量子接口

• 批准号: EP/N003527/1
• 负责人: Jonathan Pritchard
• 金额: $ 95.69万
• 依托单位: University of Strathclyde
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FN003527%2F1
• 关键词: Hybrid; Atom; Photon; Superconductor; Quantum

The field of quantum information arises from a desire to overcome the challenges of solving complex or intractable problems on classical computers by harnessing quantum mechanics to provide efficient and scalable algorithms. Whilst there has been tremendous recent progress in the realisation of small-scale quantum circuits comprising several quantum bits (``qubits''), research indicates that a fault-tolerant quantum computer capable of harnessing the power of quantum mechanics will require a network of thousands of qubits. This goal is presently beyond the reach of any existing implementation based on a single physical qubit type.Hybrid quantum information processing is an alternative approach that exploits the unique strengths of disparate quantum technologies, and offers a route to overcome the drawbacks associated with of a single-qubit architecture in direct analogy to the design of classical computing hardware. This proposal aims to combine three different technologies: i) Superconducting circuits, with very fast (10 ns) gate times for fast processing, ii) Neutral atoms, with long (10 s) coherence times for long lived quantum memory, iii) Optical photons, for long distance fibre communication,to create a novel hybrid quantum interface capable of storing, processing and generating highly entangled states of photons for quantum networking and cryptography applications, overcoming the short coherence time associated with the scalable superconducting circuit systems. This also offers applications in quantum metrology for conversion from optical to microwave domain quantum information, making it possible to extend the interface to incorporate a wide range of alternative solid-state based qubits.The interface relies on use of highly excited Rydberg states, which have incredibly large dipole moments and transitions in the microwave regime, which can resonantly couple to superconducting qubits embedded in planar microwave waveguide cavities. The large Rydberg dipole also leads to strong, controllable interactions between atoms to provide a collective enhancement in the coupling to single photons for efficient storage and retrieval of light.The first stage of the experiment is to trap spatially addressable atomic ensembles above a superconducting microwave resonator operating at 4 K to demonstrate strong coupling to the waveguide mode, a key milestone for implementing the hybrid interface. The ensembles will then be utilised to perform coherent storage and retrieval of optical photons, as well as generation of single photons using four-wave mixing. The second stage is to exploit the off-resonant interaction with the cavity to achieve controllable long distance (~1 cm) entanglement between a pair of ensembles trapped within a single microwave resonator. This will then be used to generate entangled photon pairs, exploring the benefits of collective encoding within the ensembles for achieving entanglement in the polarisation degrees of freedom for long-distance cryptographic quantum key distribution. The resulting hybrid quantum interface provides an ideal building block for establishing quantum networks. Long term this can be integrated with existing superconducting qubit technologies, making a significant step towards the realisation of scalable quantum computing.

量子信息领域的出现是因为人们希望通过利用量子力学来提供高效和可扩展的算法，从而克服在经典计算机上解决复杂或棘手问题的挑战。虽然最近在实现包括几个量子比特（“量子比特”）的小规模量子电路方面取得了巨大进展，但研究表明，能够利用量子力学的容错量子计算机将需要数千个量子比特的网络。混合量子信息处理是一种利用不同量子技术的独特优势的替代方法，它提供了一种克服与经典计算硬件设计直接类似的单量子位架构相关的缺点的途径。该提案旨在将联合收割机三种不同的技术结合起来：i）超导电路，具有用于快速处理的非常快（10 ns）的门时间，ii）中性原子，具有用于长寿命量子存储器的长（10 s）相干时间，iii）光学光子，用于长距离光纤通信，以创建能够存储的新型混合量子接口，处理和产生用于量子网络和密码学应用的光子的高度纠缠态，克服与可扩展超导电路系统相关联的短相干时间。这也为量子计量学提供了从光域到微波域量子信息转换的应用，使得扩展界面以包含广泛的替代固态量子比特成为可能。该界面依赖于使用高度激发的里德伯态，其在微波区具有令人难以置信的大偶极矩和跃迁，其可以谐振耦合到嵌入在平面微波波导腔中的超导量子位。大的里德伯偶极子也导致原子之间的强，可控的相互作用，提供一个集体增强耦合到单个光子的有效存储和检索的光。实验的第一阶段是在超导微波谐振器上运行在4 K的空间可寻址的原子系综陷阱，以证明强耦合到波导模式，实现混合接口的一个关键里程碑。然后，将利用这些集合来执行光学光子的相干存储和检索，以及使用四波混频产生单光子。第二阶段是利用与腔的非共振相互作用来实现被捕获在单个微波谐振器内的一对系综之间的可控长距离（~ 1cm）纠缠。然后，这将被用来生成纠缠光子对，探索合奏内的集体编码的好处，以实现长距离加密量子密钥分发的偏振自由度的纠缠。由此产生的混合量子接口为建立量子网络提供了理想的构建块。从长远来看，这可以与现有的超导量子比特技术集成，朝着实现可扩展的量子计算迈出重要一步。

项目成果

Demonstration of a Quantum Gate Using Electromagnetically Induced Transparency.

• DOI: 10.1103/physrevlett.129.200501
• 发表时间: 2022-04
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: K. McDonnell;L. Keary;J. Pritchard

Sub-kHz excitation lasers for Quantum Information Processing with Rydberg atoms

用于里德伯原子量子信息处理的亚 kHz 激发激光器

• DOI: 10.48550/arxiv.1711.02645
• 发表时间: 2017
• 作者: Legaie R

Strong coupling and active cooling in a finite temperature hybrid atom-cavity system

有限温度混合原子腔系统中的强耦合和主动冷却

• DOI: 10.48550/arxiv.2108.01386
• 发表时间: 2021
• 作者: Keary L

Demonstration of a Quantum Gate using Electromagnetically Induced Transparency

使用电磁感应透明的量子门演示

• DOI: 10.48550/arxiv.2204.03733
• 发表时间: 2022
• 作者: McDonnell K

Hybrid quantum devices: Guest editorial

• DOI: 10.1063/5.0057740
• 发表时间: 2021-06
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Y. Chu;J. Pritchard;Hailin Wang;M. Weides