title: Terahertz radiation by an ultrafast spontaneous polarization modulation of multiferroic BiFeO3 thin films.
abstract: Terahertz (THz) radiation has been observed from multiferroic BiFeO3 thin films via ultrafast modulation of spontaneous polarization upon carrier excitation with illumination of femtosecond laser pulses. The radiated THz pulses from BiFeO3 thin films were clarified to directly reflect the spontaneous polarization state, giving rise to a memory effect in a unique style and enabling THz radiation even at zero-bias electric field. On the basis of our findings, we demonstrate potential approaches to ferroelectric nonvolatile random access memory with nondestructive readability and ferroelectric domain imaging microscopy using THz radiation as a sensitive probe.
authors.affiliation: Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Kouhei
authors.initials: K
authors.lastname: Takahashi
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kida
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Tonouchi