Slim Jesse J, Del Pino Javier, Verhagen Ewold
Center for Nanophotonics, AMOLF, Amsterdam, The Netherlands.
Australian Research Council Centre of Excellence for Engineered Quantum Systems (EQUS), School of Mathematics and Physics, University of Queensland, St Lucia, QLD, Australia.
Nat Commun. 2025 Aug 12;16(1):7471. doi: 10.1038/s41467-025-62541-z.
Artificial magnetic fields break time-reversal symmetry in engineered materials-also known as metamaterials, enabling robust, topological transport of neutral excitations, much like edge channels facilitate electronic conduction in the integer quantum Hall effect. We experimentally demonstrate the emergence of quantum-Hall-like chiral edge states in optomechanical resonator networks. Synthetic magnetic fields for phononic excitations are induced through laser drives, while cavity optomechanical control allows full reconfigurability of the effective metamaterial response of the networks, including programming of magnetic fluxes in multiple resonator plaquettes. By tuning the interplay between network connectivity and magnetic fields, we demonstrate both flux-sensitive and flux-insensitive localized mechanical states. Scaling up the system creates spectral features that are precursors to Hofstadter butterfly spectra. Site-resolved spectroscopy reveals edge-bulk separation, with stationary phononic distributions signaling chiral edge modes. We directly probe those edge modes in transport measurements to demonstrate a unidirectional acoustic channel. This work unlocks new ways of controlling topological phononic phases at the nanoscale with applications in noise management and information processing.
人工磁场打破了工程材料（也称为超材料）中的时间反演对称性，实现了中性激发的稳健拓扑输运，这与边缘通道在整数量子霍尔效应中促进电子传导非常相似。我们通过实验证明了光机械谐振器网络中出现了类似量子霍尔效应的手性边缘态。通过激光驱动诱导声子激发的合成磁场，而腔光机械控制允许对网络的有效超材料响应进行完全重新配置，包括对多个谐振器斑块中的磁通量进行编程。通过调整网络连通性和磁场之间的相互作用，我们展示了对通量敏感和不敏感的局域机械状态。扩大系统规模会产生一些光谱特征，这些特征是霍夫施塔特蝴蝶光谱的前兆。位点分辨光谱揭示了边缘与体相的分离，静态声子分布表明了手性边缘模式。我们在输运测量中直接探测这些边缘模式，以证明单向声学通道。这项工作开启了在纳米尺度上控制拓扑声子相的新方法，可应用于噪声管理和信息处理。
