基于二维量子随机行走实验的专用量子计算应用研究

Analog quantum computing maps certain computing tasks onto the coupling matrix of a quantum evolution system, and the specific chips designed according to a required algorithm could be applied to a certain task such as searching, simulation and optimization in various fields including engineering, finance, bio-medicine, etc. Based on large-scale photonic chips, our research team has realized the world’s first real spatial two-dimensional quantum walk, and the first experimental demonstration of ‘fast hitting’, an important algorithm using quantum walks. The two progresses were recently published in Science Advances and Nature Photonics, respectively. Comparing with pure quantum walks, there’s a more comprehensively existed form of walk, the quantum stochastic walks, which are the blending of pure quantum walk and classical random walk. Both quantum stochastic walks and quantum walks are important tools for analog quantum computing. However, current experimental research and application demonstration for quantum stochastic walks remain at a very elementary stage. ..This project would aim at the experimental research of quantum simulation and quantum optimization using two-dimensional quantum stochastic walks. The experimental applications include multidisciplinary topics on simulating energy transport in the photosynthesis process and realizing the ‘associative memory’ in Hopfield neural network, both by quantum stochastic walks implemented on our large-scale integrated photonic chip. This project also covers the design of an efficient program solver of large-scale quantum stochastic walks, which can be applied to quantum PageRank as a counterpart to Google’s PageRank algorithm for complex networks. This project would broaden the frontiers of applications for analog quantum computing using quantum stochastic walks.

专用量子计算将特定计算任务对应量子系统耦合矩阵，设计专用芯片可广泛应用于不同领域中的各种搜索、模拟、优化等问题。申请人基于大规模光子芯片，已实现首个空间二维量子行走及首个量子行走“快速到达”加速算法实验演示，成果分别在Science Advances 和Nature Photonics上发表。一种比纯量子行走更普遍的形式是量子随机行走，它是量子行走和经典随机行走的混合，也是专用量子计算的重要工具，但是目前量子随机行走实验和应用研究处在非常基础阶段。.本项目将开展基于二维量子随机行走的量子模拟和优化问题的实验研究，应用于实验模拟开放量子系统对生物光合作用的影响、实现Hopfield神经网络“联想记忆”用于图像识别等学科交叉研究，同时推出大规模量子随机行走优化算法工具包，实现相对于谷歌PageRank的量子网页排序算法并指导更多应用探索。项目旨在拓展基于量子随机行走的专用量子计算全面应用场景。

本项目在专用量子计算逐渐面向应用拓展的研究背景下，通过飞秒激光直写技术制备光波导芯片，运用大规模三维波导的演化空间，以及丰富的精准波导调控技术手段，构建各种丰富的量子行走哈密顿量，从而映射各种应用问题，探讨拓展专用量子计算应用。.本项目已取得较好的科研成果。基于飞秒激光直写的量子随机行走芯片实验已实现大规模哈尔随机的制备，可用于玻色采样专用量子计算，相应工作在Physical Review Letters中发表。基于光量子芯片上周期性弯折的量子行走实验，展示模拟动态局域的优势，并可实现片上量子态存储，相应工作在Photonics Research中发表。基于光量子芯片实现粘合二叉树的一维等效结构上的量子快速到达算法，相对于经典到达算法具有指数级加速，相应工作在Optica中发表。诸如以上，基于飞秒激光直写技术制备光量子芯片，开展了量子行走前沿科学实验研究，实现一系列可面向应用拓展的研究工作。在本项目的支持下，发表SCI论文5篇，指导硕士生2位，均已硕士毕业。项目完成既定目标并具有充分的科学意义。