High Carrier Mobility Coupled with Quantum Paraelectric Fluctuation

Abstract

Photoconductivity and photo-magneto-transport properties have been measured in quantum paraelectric and ferroelectric SrTiO ₃ crystals. We have found a large isotope effect on the conductivity of photo-carrier in this system. This isotope effect strongly suggests a close correlation between the quantum fluctuations and the giant photoconductivity in the quantum paraelectric system. Here we propose the possibility of the control of the carrier motion by using the external electric field. These results may become a key to understand the behavior of the carrier in the dense electric dipoles with so called as quantum fluctuation.

Keywords:

• conductivity of photo-carrier
• quantum paraelectricity
• quantum fluctuation
• isotope effect
• SrTiO₃

Acknowledgment

This work has been supported in part by a Grant-in-Aid for Encouragement of Young Scientists from Japan Society for the Promotion of Science, Grant No. 18740179.