Dielectric tunability of SrTiO3 thin films in the terahertz range

P. Kužel, F. Kadlec, H. Němec, R. Ott, E. Hollmann, N. Klein
2006 Applied Physics Letters  
We have developed an interdigited electrode structure for applying a static electric field to a ferroelectric thin film, which enables nearly full transmission of a perpendicularly polarized terahertz wave. This approach has been used to determine the electric field dependence of the complex permittivity of a SrTiO 3 thin film on a sapphire substrate up to about 2 THz employing time-domain terahertz spectroscopy. We have demonstrated up to 10% variation of the film permittivity at 300 GHz at
more » ... ty at 300 GHz at room temperature induced by an applied electric field of 100 kV/ cm. No dielectric dispersion is observed between 1 MHz and about 500 GHz. The field-induced changes are attributed to soft mode hardening.
doi:10.1063/1.2183370 fatcat:mhjsdagi7razvb6brqmj26hqka