Terahertz-Field-Induced Large Macroscopic Polarization and Domain-Wall Dynamics in an Organic Molecular Dielectric.
A rapid polarization control in paraelectric materials is important for an ultrafast optical switching useful in the future optical communication. In this study, we applied terahertz-pump second-harmonic-generation-probe and optical-reflectivity-probe spectroscopies to the paraelectric neutral phase of an organic molecular dielectric, tetrathiafulvalene-p-chloranil and revealed that a terahertz pulse with the electric-field amplitude of ∼400  kV/cm produces in the subpicosecond time scale a large macroscopic polarization whose magnitude reaches ∼20% of that in the ferroelectric ionic phase. Such a large polarization generation is attributed to the intermolecular charge transfers and breathing motions of domain walls between microscopic neutral and ionic domains induced by the terahertz electric field.
Department of Advanced Materials Science, University of Tokyo, Kashiwa 5-1-5, Chiba 277-8561, Japan.
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Morimoto
Department of Advanced Materials Science, University of Tokyo, Kashiwa 5-1-5, Chiba 277-8561, Japan.
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Miyamoto
Department of Advanced Materials Science, University of Tokyo, Kashiwa 5-1-5, Chiba 277-8561, Japan.
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Yamakawa
Department of Advanced Materials Science, University of Tokyo, Kashiwa 5-1-5, Chiba 277-8561, Japan.
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Terashige
Department of Advanced Materials Science, University of Tokyo, Kashiwa 5-1-5, Chiba 277-8561, Japan.
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Ono
Department of Advanced Materials Science, University of Tokyo, Kashiwa 5-1-5, Chiba 277-8561, Japan.
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Kida
Department of Advanced Materials Science, University of Tokyo, Kashiwa 5-1-5, Chiba 277-8561, Japan.
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Okamoto