High-order harmonic generation (HHG) in solids opens new frontiers in ultrafast spectroscopy of carrier and field dynamics in condensed matter, picometer resolution structural lattice characterization and designing compact platforms for attosecond pulse sources. Nanoscale structuring of solid surfaces provides a powerful tool for controlling the spatial characteristics and efficiency of the harmonic emission. Here we study HHG in a prototypical phase-change material Ge2Sb2Te5 (GST). In this material the crystal phase can be reversibly changed between a crystalline and amorphous phase by light or electric current mediated methods. We show that optical phase-switching is fully reversible and allows for dynamic control of harmonic emission. This introduces GST as new addition to materials that enable flexible metasurfaces and photonic structures that can be integrated in devices and allow for ultrafast optical control.

中文翻译：

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GeSbTe 纳米薄膜中可调谐高次谐波的产生

固体中的高阶谐波产生（HHG）开辟了凝聚态物质中的超快载流子光谱和场动力学、皮米分辨率结构晶格表征以及阿秒脉冲源紧凑平台设计的新领域。固体表面的纳米级结构为控制谐波发射的空间特征和效率提供了强大的工具。在这里，我们研究了原型相变材料 Ge 中的 HHG2锑2碲5（消费税）。在这种材料中，晶相可以通过光或电流介导的方法在晶相和非晶相之间可逆地改变。我们证明光学相位切换是完全可逆的，并且允许动态控制谐波发射。这引入了 GST 作为材料的新补充，可实现灵活的超表面和光子结构，这些结构可以集成到设备中并允许超快光学控制。