HfO2-based ferroelectric modulator of terahertz waves with graphene metamaterial
Jiang Ran1, †, , Wu Zheng-Ran2, Han Zu-Yin3, Jung Hyung-Suk2
       

Basic spectra for grapheme and modulator. (a) Raman spectrum of the graphene with the inset showing the close-up view of a unit cell with W = 15 μm and L = 60 μm. (b) Normalized terahertz time-domain signals at various gate bias voltages under a photoexcitation power of 300 mW.