FET: Small: Decoding Quantum Error-Correcting Codes for Quantum Computing and Communication

FET：小型：解码量子计算和通信的量子纠错码

• 批准号: 2316713
• 负责人: Todd Brun
• 金额: $ 60万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-12-01 至 2026-11-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2316713&HistoricalAwards=false
• 关键词: FET; Small; Decoding; Quantum; Error

Quantum computers promise to solve many difficult computational tasks that strain the abilities of ordinary (classical) computers, especially in simulating quantum-mechanical systems and finding optimal solutions to a variety of mathematical problems. However, building large-scale quantum computers requires overcoming the challenge of decoherence, or quantum noise. The general answer to this is known: quantum error correction, to achieve fault-tolerant quantum computation. The current generation of noisy, intermediate scale quantum (NISQ) processors are too small and noisy to take real advantage of quantum error correction (QEC), but as they grow in size and improve in quality, this will soon become possible. Fully fault-tolerant quantum computing (FTQC) is very demanding; but some elements of fault-tolerance should be possible in the next few years. This project aims to develop methods of fault-tolerant quantum computation that will be practical in near-term machines. The approach uses quantum teleportation to process quantum bits (qubits) stored in efficient quantum codes that protect them against decoherence. his award will support Ph.D. students working towards their degrees, and will enrich the broad educational efforts at the University of Southern California. These efforts now include not only faculty, postdocs and Ph.D. students, but master's students in the MS program in Quantum Information Science, and a growing number of undergraduate students.This project will build upon an approach based on encoding logical qubits in multi-qubit block codes with high rates. In the very near term it will be possible to use quantum error-detecting codes that encode n–2 logical qubits in n physical qubits, with a universal set of encoded gates. Such a scheme cannot be fully fault-tolerant, but it can be weakly fault-tolerant, able to detect any single fault by a final (or intermediate) measurement and post-select on no error being detected. For small computations this will give an improvement over an unencoded quantum circuit. As qubit counts increase and noise rates diminish, more elements of FTQC can be added until full fault-tolerance is achieved. This project will also tackle the problem of preparing ancilla states, which are the building blocks of teleportation-based FTQC by combining state preparation and verification into a single process, using a combination of flag-based methods and error detection. The investigators will also pursue fast and accurate decoding algorithms for QEC codes that could be used in real time during a quantum computation. This project will develop decoding algorithms via machine learning methods. In addition, the project will explore applications of QEC codes to other problems in quantum information science. TThis award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

量子计算机有望解决许多困难的计算任务，这些任务对普通（经典）计算机的能力提出了挑战，特别是在模拟量子力学系统和寻找各种数学问题的最佳解决方案方面，然而，构建大规模量子计算机需要克服这一挑战。退相干或量子噪声的一般答案是已知的：量子纠错，以实现容错量子计算当前一代的噪声中级量子（NISQ）处理器太小且噪声太大，无法进行实际处理。量子纠错（QEC）的优势，但随着它们规模的扩大和质量的提高，完全容错的量子计算（FTQC）很快就会成为可能，但容错的某些要素应该是可能的。该项目旨在开发可在近期机器中实用的容错量子计算方法，该方法使用量子隐形传态来处理存储在高效量子代码中的量子位（量子位），以防止其退相干。他的奖项将支持博士生攻读学位，并将丰富南加州大学的广泛教育工作，这些工作现在不仅包括教师、博士后和博士生，还包括量子硕士项目的学生。信息科学和越来越多的本科生。该项目将建立在一种基于多量子位块代码中高速率编码逻辑量子位的方法的基础上，在不久的将来，将有可能使用量子错误检测代码。对 n–2 逻辑进行编码n 个物理量子位中的量子位，具有通用的编码门集，这样的方案不能完全容错，但它可以是弱容错的，能够通过最终（或中间）测量和后期检测来检测任何单个故障。对于小型计算，这将比未编码的量子电路有所改进，随着量子位计数的增加和噪声率的降低，可以添加更多的 FTQC 元素，直到实现完全容错。该项目还将解决准备辅助状态的问题，这些状态是基于隐形传输的 FTQC 的构建块，通过将状态准备和验证结合到一个过程中，使用基于标志的方法和错误检测的组合。研究人员还将追求快速。以及可在量子计算过程中实时使用的 QEC 代码的精确解码算法。此外，该项目还将探索 QEC 代码在量子信息科学中的其他问题的应用。奖项反映通过使用基金会的智力价值和更广泛的影响审查标准进行评估，NSF 的法定使命被认为值得支持。