Photoinduced metallic state in VO2 proved by the terahertz pump-probe spectroscopy
2008; American Institute of Physics; Volume: 92; Issue: 1 Linguagem: Inglês
10.1063/1.2830664
ISSN1520-8842
AutoresMakoto Nakajima, Naoko Takubo, Zenji Hiroi, Yutaka Ueda, Tohru Suemoto,
Tópico(s)Advanced Memory and Neural Computing
ResumoWe investigated the ultrafast terahertz response to the photoexcitation for vanadium dioxide single crystals and thin films using the optical-pump terahertz-probe technique at room temperature. The optical excitation induced an ultrafast decrease of the transmittance of the terahertz radiation within 0.7ps. Since we expect only the free carrier response in the terahertz range, the decrease of the transmittance is unambiguously assigned to the appearance of the high electronic conductivity due to free carriers. The conductivity increases more than ten times in the picosecond time range after photoexcitation and it is concluded that the electronic states are metallic.
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