Integrating quantum sensors with bespoke quantum error correction

将量子传感器与定制量子纠错集成

• 批准号: EP/W028115/1
• 负责人: Yingkai Ouyang
• 金额: $ 142.17万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Fellowship
• 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%2FW028115%2F1
• 关键词: Integrating; quantum; sensors; bespoke; error

Physical quantities such as time, phase, and entanglement cannot be measured directly, but instead must be inferred through indirect measurements. An important category of such indirect measurements is parameter estimation. Ideal quantum sensors would estimate physical quantities with unprecedented precision, but practical quantum sensors lose their quantum advantage because of noise. Incorporating quantum error correction codes into quantum sensors is an attractive theoretical approach to reduce noise, but is beset with practical difficulties. Namely, most quantum error correction codes (1) cannot be readily prepared in actual physical systems, (2) would introduce more errors than they correct during imperfect quantum error correction, and (3) can destroy the signal meant to be measured during quantum error correction.Most quantum error correction schemes are studied by abstracting away the physics of sensors, while quantum sensors are typically studied in the absence of quantum error correction. Mainstream approaches treat both quantum sensors and quantum error correction components as black boxes to be optimised separately. This project aims to break down the boundary between the quantum error correction black box and the quantum sensor black box, and integrate them to make an overall quantum error correction-integrated quantum sensor, by optimising over bespoke quantum error correction codes.A critical problem that using bespoke quantum error correction codes in optimising quantum sensors can overcome is the intractability of current numerical approaches in optimising quantum error correction codes for quantum sensors. These numerical methods impose no apriori structure on quantum error correction codes, and suffer from a runtime that increases exponentially in the number of particles. By choosing bespoke quantum codes that can be described with a tractable number of parameters, quantum sensors can be numerically optimised with respect to these codes in a scalable way.A prominent family of bespoke quantum error correction codes that this project will consider are symmetric codes. These codes are invariant under any permutation of the underlying particles, and have other practical advantages apart from the scalability in their numerical optimisations. First symmetric codes are very promising candidates for near-term implementation in physical devices, because their controllability by global fields could allow for their scalable physical implementations in near-term devices where addressability without cross-talk is difficult. Second, such symmetric codes can correct untracked particle losses, which are impossible to correct using conventional quantum error correction codes.This project will find optimal bespoke quantum error correction codes that maximise the quantum advantage attainable in the quantum estimation of classical fields, while also being easy to prepare in actual physical systems. The performance of symmetric codes will be compared with the performance of other families of bespoke quantum error correction codes. In the mathematical optimisation of the quantum sensor's precision, the project will take an integrated approach. Namely, the physical constraints of the quantum sensor such as the number of allowed qubits, operating temperature, and energy budget will be fixed, and the best quantum error correction codes for quantum sensors will be found. In doing so, this project will provide theoretical blueprints on how sensitivities of quantum sensors may be improved using existing quantum hardware.

时间，相和纠缠等物理量不能直接测量，而必须通过间接测量来推断。这种间接测量的重要类别是参数估计。理想的量子传感器将以前所未有的精度估算物理量，但是实际量子传感器由于噪声而失去量子优势。将量子误差校正代码纳入量子传感器是一种有吸引力的理论方法，可以减少噪声，但会受到实际困难的困扰。也就是说，大多数量子误差校正代码（1）不能在实际的物理系统中容易准备，（2）将引入比在不完善的量子误差校正期间更正确的错误，并且（3）可以破坏在量子误差校正期间要测量的信号。大多数量子误差校正方案通过量子校正来抽象量子校正，而量子误差则在量子上校正了，而量子的校正是在量子上校正的。主流方法将量子传感器和量子误差校正组件视为要分别优化的黑匣子。该项目旨在通过对空位误差校正代码进行优化，通过优化量子误差校正代码进行优化，使用BESPOKE量子校正量验证量子验证量的量子验证量的关键方法，可以使量子校正率在数值方面，从而优化了当前的数值，从而使量子误差校正代码在当前数值中进行优化，量子误差校正代码是优化的，从而优化了当前的数值。这些数值方法对量子误差校正代码没有任何APRIORI结构，并且遭受了粒子数量成倍增加的运行时。通过选择可以用可拖动的参数描述的定制量子代码，可以以可扩展的方式对这些代码进行数值优化量子传感器。该项目将考虑该项目将考虑的一个著名的定制量子误差校正代码是对称代码。这些代码在基础粒子的任何排列下都是不变的，除了其数值优化的可伸缩性外，还具有其他实际优势。首先对称代码是在物理设备中近期实施的非常有前途的候选人，因为它们的全球可控性可以允许在没有交叉通话的无通话性的近期设备中进行可扩展的物理实现。其次，这种对称代码可以纠正未跟踪的粒子损耗，使用常规量子误差校正代码无法纠正，该项目将找到最佳的定制量子误差校正代码，以最大程度地利用经典字段的量子估计中获得的量子优势，同时也容易在实际物理系统中进行准备。对称代码的性能将与其他定制量子误差校正代码的其他家族的性能进行比较。在量子传感器精度的数学优化中，该项目将采用一种集成的方法。也就是说，将固定量子传感器的物理约束，例如允许的Qubits，工作温度和能量预算的数量，并找到最佳的量子误差校正代码。这样一来，该项目将提供有关如何使用现有量子硬件改善量子传感器敏感性的理论蓝图。

项目成果

Approximate reconstructability of quantum states and noisy quantum secret sharing schemes

• DOI: 10.1103/physreva.108.012425
• 发表时间: 2023-02
• 期刊: ArXiv
• 作者: Yingkai Ouyang;K. Goswami;J. Romero;B. Sanders;Min-Hsiu Hsieh;M. Tomamichel