近日，美国马里兰大学的Avik Dutt及其研究团队取得一项新进展。经过不懈努力，他们成功利用驱动耗散光子分子实现Floquet合成维中的量子化拓扑泵浦。相关研究成果已于2024年2月26日在国际知名学术期刊《自然—物理学》上发表。
该研究团队引入了一个受耗散的光子分子和几个射频和光学驱动器，作为观测沿Floquet合成维量子化输运的候选系统。研究人员描述了对比拓扑阶段和平凡阶段的初步实验。该平台的驱动和耗散特性增强了非相干调制光子分子的拓扑能量泵浦。
此外，研究人员还提出了一种实现Weyl点的方法，并成功测量了从这些倒易空间磁单极子发出的Berry曲率，阐明了在该平台上进行高维拓扑哈密顿模拟的能力。该研究方法能够利用远低于集成光子腔自由光谱范围的调制带宽，直接进行各种哈密顿量的k空间工程。
据悉，拓扑效应的核心特征是拓扑不变量，这些不变量通常是整数值，并在空间、时间和其他自由度上创造出稳健的量子化输运通道。特别是，时间通道为研究者提供了一种独特的方式，即通过利用几个不相称的频率来驱动系统，从而实现高维拓扑效应。然而，耗散现象通常会对这种拓扑效应产生不利影响。
附：英文原文
Title: Quantized topological pumping in Floquet synthetic dimensions with a driven dissipative photonic molecule
Author: Sridhar, Sashank Kaushik, Ghosh, Sayan, Srinivasan, Dhruv, Miller, Alexander R., Dutt, Avik
Issue&Volume: 2024-02-26
Abstract: Topological effects are characterized by topological invariants, which are typically integer-valued, and lead to robust quantized transport channels in space, time and other degrees of freedom. The temporal channel in particular allows one to achieve higher-dimensional topological effects by driving the system with several incommensurate frequencies. However, dissipation is generally detrimental to such topological effects. Here we introduce a photonic molecule subjected to dissipation and several radio-frequency and optical drives as a candidate system for observing quantized transport along Floquet synthetic dimensions. We describe preliminary experiments contrasting the topological and trivial phases. Topological energy pumping in the incommensurately modulated photonic molecule is enhanced by the driven and dissipative nature of our platform. Furthermore, we provide a path for realizing Weyl points and measuring the Berry curvature emanating from these reciprocal-space magnetic monopoles and illustrate the capabilities for higher-dimensional topological Hamiltonian simulation in this platform. Our approach enables direct k-space engineering of a wide variety of Hamiltonians using modulation bandwidths that are well below the free spectral range of integrated photonic cavities.
DOI: 10.1038/s41567-024-02413-3
Source: https://www.nature.com/articles/s41567-024-02413-3