Photoinduced metallic state in VO2 proved by the terahertz pump-probe spectroscopy
Photoinduced metallic state in VO2 proved by the terahertz pump-probe spectroscopy
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DOI：
10.1063/1.2830664
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发表时间：
2008-01-07
影响因子：
4
通讯作者：
Suemoto, T.
中科院分区：
文献类型：
--
作者：
Nakajima, M.;Takubo, N.;Suemoto, T.
利用光泵太赫兹探测技术，在室温下研究了二氧化钒单晶和薄膜的超快太赫兹响应。光激发导致太赫兹辐射透过率在0.7ps内超快下降。由于我们预计只有太赫兹范围内的自由载流子响应，透过率的降低明确地归因于自由载流子导致的高电子传导性的出现。在光激发后的皮秒时间范围内，电导率增加了十倍以上，并得出结论，电子态是金属的。
We 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 0.7 ps. 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.