Abstract-Active KTaO3 hybrid terahertz metamaterial

• Liang Wu, 
• Jinglong Liu, 
• Hui Li, 
• Chunfeng Ding, 
• Ningning Xu, 
• Xiaolei Zhao, 
• Zongcheng Xu, 
• Quan Sheng, 
• Jianquan Yao, 
• Jining Li, 
• Xin Ding & 
• Weili Zhang

https://www.nature.com/articles/s41598-017-05529-0

The dielectric properties of an active KTaO3 hybrid metamaterial structure and its tunability under external electric fields are investigated at room temperature by means of terahertz time-domain spectroscopy. Application of the electric field leads to an appreciable tuning of the dielectric loss, which is up to 17%. Meanwhile, the refractive index also changes appreciably. These findings are attributed to the internal space charge field in the crystal caused by the excited free carriers.