Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Centre for Disruptive Photonic Technologies, The Photonic Institute, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Adv Mater. 2019 Mar;31(12):e1808157. doi: 10.1002/adma.201808157. Epub 2019 Jan 27.
The strikingly contrasting optical properties of various phases of chalcogenide phase change materials (PCM) has recently led to the development of novel photonic devices such as all-optical non-von Neumann memory, nanopixel displays, color rendering, and reconfigurable nanoplasmonics. However, the exploration of chalcogenide photonics is currently limited to optical and infrared frequencies. Here, a phase change material integrated terahertz metamaterial for multilevel nonvolatile resonance switching with spatial and temporal selectivity is demonstrated. By controlling the crystalline proportion of the PCM film, multilevel, non-volatile, terahertz resonance switching states with long retention time at zero hold power are realized. Spatially selective reconfiguration at sub-metamaterial scale is shown by delivering electrical stimulus locally through designer interconnect architecture. The PCM metamaterial also features ultrafast optical modulation of terahertz resonances with tunable switching speed based on the crystalline order of the PCM film. The multilevel nonvolatile, spatially selective, and temporally tunable PCM metamaterial will provide a pathway toward development of novel and disruptive terahertz technologies including spatio-temporal terahertz modulators for high speed wireless communication, neuromorphic photonics, and machine-learning metamaterials.
各种碲化物相变型材料（PCM）的光学性质差异显著，这促使人们开发出了新型光子器件，如全光非冯·诺依曼存储器、纳米像素显示器、颜色渲染和可重构纳米等离子体等。然而，碲化物光子学的探索目前仅限于光学和红外频率。在此，展示了一种集成相变材料的太赫兹超材料，用于具有空间和时间选择性的多级非易失性共振开关。通过控制 PCM 薄膜的结晶比例，实现了具有长时间保持零功耗的多级、非易失性、太赫兹共振开关状态。通过通过设计的互连架构局部传输电刺激，显示出亚超材料尺度的空间选择性重构。PCM 超材料还具有超快的太赫兹共振光调制功能，其开关速度可基于 PCM 薄膜的结晶有序性进行调节。这种多级非易失性、空间选择性和时间可调谐的 PCM 超材料将为开发新型颠覆性的太赫兹技术提供途径，包括用于高速无线通信、神经形态光子学和机器学习超材料的时空太赫兹调制器。
