Berardi Sensale-Rodriguez and Ajay Nahata Terahertz Conductivity Measurements of the High Electron Density at the Interface Between Complex Oxides Berardi Sensale-Rodriguez and Ajay Nahata Objective: Explore the potential for obtaining very high electron concentrations at the interface between two complex oxides and examine its relevance for terahertz (THz) applications. Approach: Study the THz transmittance as a function of temperature through multiple samples. Correlate the THz conductivity with DC measurements. Results and Significance: The results show a large room temperature THz conductivity that is 3-6 times larger than measured using DC measurements. The measured THz conductivity in these samples are similar to that of high-mobility semiconductors and CVD graphene, making complex oxide materials well suited for THz device applications. Measured (left) and modeled (right) THz transmittance through two complex oxide samples. The extracted mobilities are ~13 – 19 cm2/Vs. THz transmittance vs. temperature through epitaxial structure, along with a schematic diagram of the sample. The measured THz conductivity at 250K is 1.56 mS, which is comparable to values obtained for quality large area CVD graphene. Top Figures: Measured (left) and modeled (right) THz transmittance through two NTO/STO samples. From DC measurements, the extracted mobilities and carrier densities for samples #102 and #103 are: 4.11 and 3.36 cm2/Vs, and 7.16 x 1014 and 3.64 x 1014 cm-2, respectively. From THz measurements, the extracted mobilities are 13 cm2/Vs and 19 cm2/Vs, respectively. Bottom Figure: THz transmittance vs. temperature through a STO/NTO/STO sample. The epitaxial structure of the sample is depicted in the inset. The extracted THz conductivity at 250K is 1.56mS, which is comparable to levels attainable in typical quality large area CVD graphene. S. Arezoomandan, H. Condori, A. Chanana, P. Xu, A. Nahata, B. Jalan and B. Sensale-Rodriguez, submitted.