Reconfigurable and Nonvolatile Terahertz Metadevices Based on a Phase-Change Material

Reconfigurable terahertz (THz) devices with nonvolatile and multilevel properties are highly desirable in many applications from imaging and high-capacity communication to nondestructive biosensing. Here, we present and experimentally demonstrate a promising platform for dynamic THz devices by exploring the reversible, nonvolatile, and multilevel modulation features of the Ge2Sb2Te5 (GST) material. These properties were fully demonstrated by characterizing the THz response of a centimeter-level area GST layer during the thermally stimulated crystallization and optically stimulated reamorphization process. As a proof of concept, a hybrid plasmonic dimer structure composed of two trapezoidal metallic rings connected by GST islands was designed, fabricated, and characterized. The modulation of this device was experimentally realized by inducing crystallization and reamorphization processes with thermal and optical activation, respectively. Moreover, electrical switching of the designed device was also realized by applying a 5 s duration electrical pulse. With these findings, this study may open an attractive direction for a wide range of design possibilities in terms of reversible, nonvolatile, and multilevel THz modulation devices.