Error-mitigated algorithms for near-term quantum computers

量子计算机被预测能够解决某些超出当今超级计算机能力的问题。这些问题包括与太阳能电池和电池设计相关的材料系统的建模和模拟，以及其他重要的实际应用。因此，量子计算机最终可以实现快速筛选许多候选材料，以获得更高性能的电池。然而，目前的"噪声中尺度量子"（Noisy Intermediate-Scale Quantum，NISQ）量子计算机还不能实现完全的量子容错，并且会受到与环境不必要的交互所导致的错误的显著影响。本项目将开发近期的量子算法、编译策略和错误缓解技术，旨在克服或减少这些错误。这些技术可以包括基于硬件的底层噪声模型的知识重新编译量子电路，开发抗噪声的有效算法，或者设计针对特定算法或架构的错误缓解技术。文献中的先前工作已经提供了诱人的暗示，这些技术可能是有价值的，但是已知的重新编译技术仅解决特定类型的错误，并且已知的错误缓解技术通常不利用正在运行的特定算法。该项目将包括理论工作、经典计算机上的数值模拟以及在量子硬件上运行实验（取决于其可用性）。如果成功，该项目将大大扩展NISQ量子计算机的范围。该项目属于量子技术研究领域，也与ICT，数学科学和物理科学有关。该项目与量子软件初创公司Phasecraft Ltd合作，共同资助该研究。

Quantum computers are predicted to be able to solve certain problems that are beyond the capacity of today's supercomputers. These problems include the modelling and simulation of materials systems relevant to the design of solar cells and batteries, as well as other important practical applications. Quantum computers could thus ultimately enable, for example, rapid screening of many candidate materials for higher-performance batteries. However, today's "Noisy Intermediate-Scale Quantum" (NISQ) quantum computers are not yet able to implement full quantum fault-tolerance and are significantly impacted by errors caused by unwanted interactions with the environment.This project will develop near-term quantum algorithms, compilation strategies and error-mitigation techniques that aim to overcome or reduce these errors. These techniques may include recompiling quantum circuits based on the knowledge of an underlying noise model for the hardware, developing efficient algorithms that are resistant to noise, or designing error-mitigation techniques that are targeted to a particular algorithm or architecture. Previous work in the literature has provided tantalising hints that such techniques may be valuable, but known recompilation techniques only address particular types of errors, and known error-mitigation techniques usually do not take advantage of the specific algorithm being run. The project will encompass theoretical work, numerical simulations on classical computers, and running experiments on quantum hardware, subject to its availability. If successful, the project will significantly extend the reach of NISQ quantum computers.This project falls within the Quantum Technologies research area, and is also connected to ICT, Mathematical Sciences, and Physical Sciences.The project is in collaboration with Phasecraft Ltd, a quantum software startup company, who are co-funding the research.