Seiji Kojima
University of Tsukuba
Research Interests

Polar metals, in which polar crystal structure and metallicity coexists, is one of the current topics, because the polar structure is related to the long-range electrostatic fields, while it can be fully screened by the carrier electrons. I am interested in the correlation between the ferroelectric soft mode frequency and the carrier electron concentration in the doped SrTiO3 crystals. This correlation has been studied using the terahertz time domain ellipsometry (THz-TDSE) by the accurate determination of complex dielectric constants.