Insulator-to-metal transition induces large material property variations in vanadium dioxide (VO₂) over a broad frequency band. VO₂, therefore, has been introduced into metallic resonating structures to realize reconfigurable metadevices from microwave to optical wavelengths. Beyond enabling metal/VO₂ hybrid meta-atoms, in the THz regime metallic-phase VO₂ micro-structures can support strong electromagnetic resonances, offering great potential in active manipulation of THz radiation. In this paper, we show that VO₂ dipole antennas can be used to realize geometric phase coded metasurfaces for wave-front shaping and polarization rotation of THz waves. Moreover, we demonstrate that the corresponding efficiency of the THz spin Hall effect is closely related to VO₂’s THz electrical conductivity. In light of the dispersionless nature of the geometric phase, our study indicates that metasurfaces constructed by VO₂ subwavelength resonators are good candidates for active control of broadband THz radiation.

中文翻译：

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二氧化钒超颖表面的主动太赫兹自旋霍尔效应

绝缘体到金属的过渡会在很宽的频带内引起二氧化钒（VO ₂）的较大的材料性能变化。因此，VO ₂已被引入到金属谐振结构中，以实现从微波到光波长的可重构元设备。除了使金属/ VO ₂杂化原子成为可能之外，在太赫兹状态下，金属相VO ₂微观结构还可以支持强大的电磁共振，为主动控制太赫兹辐射提供了巨大的潜力。在本文中，我们表明VO ₂偶极天线可用于实现几何相位编码超表面，以进行波前成形和太赫兹波的极化旋转。此外，我们证明了THz自旋霍尔效应的相应效率与VO ₂的THz电导率密切相关。根据几何相位的无色散性质，我们的研究表明，由VO ₂亚波长谐振器构成的超表面是主动控制宽带THz辐射的良好候选者。