近日，加拿大国立科学研究院的Roberto Morandotti及其研究小组与德国耶拿大学的Ulf Peschel等人合作并取得一项新进展。经过不懈努力，他们通过可控合成时间光子晶格实现量子态处理。相关研究成果已于2024年10月14日在国际知名学术期刊《自然—光子学》上发表。
该研究团队展示了一种基于时间段纠缠光子对，在耦合光纤环路系统中实现的，在合成时间光子晶格上进行离散时间量子行走的可扩展量子处理器。研究人员利用该方案对量子态操作进行路径优化，包括生成二级和四级时间段纠缠以及相应的双光子干涉。
可编程时间光子晶格的设计使研究人员能够控制行走的动态，从而在无需后选择的情况下提高了符合计数和量子干涉测量的效率。这项研究结果表明，时间合成维度如何为高效的量子信息处理铺平道路，包括量子相位估计、玻色子采样以及在成本效益高、可扩展且稳健的光纤设置中实现高维量子系统的物质拓扑相。
据悉，光子平台上的量子行走为量子测量、模拟和通用计算提供了一个物理内涵丰富的框架。光子电路的动态可重构性是控制行走并发挥其全部操作潜力的关键。基于门控光纤环路中的时间段编码的通用量子处理方案已被提出，但由于门效率低下，尚未得到验证。
附：英文原文
Title: Quantum state processing through controllable synthetic temporal photonic lattices
Author: Monika, Monika, Nosrati, Farzam, George, Agnes, Sciara, Stefania, Fazili, Riza, Marques Muniz, Andr Luiz, Bisianov, Arstan, Lo Franco, Rosario, Munro, William J., Chemnitz, Mario, Peschel, Ulf, Morandotti, Roberto
Issue&Volume: 2024-10-14
Abstract: Quantum walks on photonic platforms represent a physics-rich framework for quantum measurements, simulations and universal computing. Dynamic reconfigurability of photonic circuitry is key to controlling the walk and retrieving its full operation potential. Universal quantum processing schemes based on time-bin encoding in gated fibre loops have been proposed but not demonstrated yet, mainly due to gate inefficiencies. Here we present a scalable quantum processor based on the discrete-time quantum walk of time-bin-entangled photon pairs on synthetic temporal photonic lattices implemented on a coupled fibre-loop system. We utilize this scheme to path-optimize quantum state operations, including the generation of two- and four-level time-bin entanglement and the respective two-photon interference. The design of the programmable temporal photonic lattice enabled us to control the dynamic of the walk, leading to an increase in the coincidence counts and quantum interference measurements without recurring to post-selection. Our results show how temporal synthetic dimensions can pave the way towards efficient quantum information processing, including quantum phase estimation, Boson sampling and the realization of topological phases of matter for high-dimensional quantum systems in a cost-effective, scalable and robust fibre-based setup.
DOI: 10.1038/s41566-024-01546-4
Source: https://www.nature.com/articles/s41566-024-01546-4