近日，英国赫瑞瓦特大学的Mehul Malik&Suraj Goel及其研究小组取得一项新进展。经过不懈努力，他们提出复杂介质中高维量子光电路的逆设计方法。相关研究成果已于2024年1月19日在国际知名学术期刊《自然—物理学》上发表。
该研究团队利用逆设计技术，将光学电路嵌入到大型环境模式混频器（如商用多模光纤）的高维空间中。这种方法使研究人员无需对每个单独的电路元件进行精确控制，同时保持了高度的可编程性。通过使用这种电路作为量子门，研究人员成功操纵了高达七个维度的高维空间模式纠缠。由于这种电路的高度可编程性，研究人员可以将多模光纤转变为通用的多结果测量设备，实现在传输通道内传输和验证纠缠态的功能。
在数值模拟的支持下，他们证明了这种方法是一种可扩展的方法，能够通过利用高维模式混频器的资源，以较低的电路深度获得较高的电路保真度。
据悉，可编程光电路是量子通信收发器和量子信息处理集成光子芯片等量子技术的重要工具。然而，在实现大范围精确控制每个单独组件的过程中，面临了巨大的挑战，导致执行的操作质量下降。此外，由于制造过程中的小缺陷被放大，这些电路的性能受到了极大的抑制。
附：英文原文
Title: Inverse design of high-dimensional quantum optical circuits in a complex medium
Author: Goel, Suraj, Leedumrongwatthanakun, Saroch, Valencia, Natalia Herrera, McCutcheon, Will, Tavakoli, Armin, Conti, Claudio, Pinkse, Pepijn W. H., Malik, Mehul
Issue&Volume: 2024-01-19
Abstract: Programmable optical circuits are an important tool in developing quantum technologies such as transceivers for quantum communication and integrated photonic chips for quantum information processing. Maintaining precise control over every individual component becomes challenging at large scales, leading to a reduction in the quality of operations performed. In parallel, minor imperfections in circuit fabrication are amplified in this regime, dramatically inhibiting their performance. Here we use inverse design techniques to embed optical circuits in the higher-dimensional space of a large, ambient mode mixer such as a commercial multimode fibre. This approach allows us to forgo control over each individual circuit element, and retain a high degree of programmability. We use our circuits as quantum gates to manipulate high-dimensional spatial-mode entanglement in up to seven dimensions. Their programmability allows us to turn a multimode fibre into a generalized multioutcome measurement device, allowing us to both transport and certify entanglement within the transmission channel. With the support of numerical simulations, we show that our method is a scalable approach to obtaining high circuit fidelity with a low circuit depth by harnessing the resource of a high-dimensional mode mixer.
DOI: 10.1038/s41567-023-02319-6
Source: https://www.nature.com/articles/s41567-023-02319-6