ISSP - The institute for Solid State Physics

Seminar
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シリーズセミナー 極限コヒーレント光科学 25回目 「1.5サイクル赤外パルスによる超高速限界電子駆動」
標題: シリーズセミナー 極限コヒーレント光科学 25回目 「1.5サイクル赤外パルスによる超高速限界電子駆動」
日時: 2014年7月24日(木)  午後1:30~
場所: 東京大学 柏図書館メディアホール  
講師: 岩井伸一郎
所属: 東北大学大学院理学研究科
要旨: Optical responses of organic charge ordered (CO) and dimer Mott insulators has attracted much attention, because they exhibit ultrafast changes in the conducting and/or dielectric properties upon photo-excitations[1-8]. Recent progress of several fs optical and ps THz pulses enables us to detect and manipulate various new aspects of the strongly correlated system.
In this study, photoinduced metal to insulator (M-I) transition was demonstrated by strong electric filed (10 MV/cm) of 1.5-cycle, 7 fs near infrared pulse in a layered organic conductor - α (ET)2I3. A large reflectivity change of > 25% and a coherent charge oscillation in time axis reflecting the CO gap have shown that the generation of CO insulator state which survives ~50 fs in the metallic phase.
Such photoinduced metal to CO insulator change is attributable to the dynamical localization, i.e., reduction of the inter-molecular transfer integral realized by high frequency strong electric field[8-10].

References:
[1] Iwai, Yamamoto et al., PRL98, 097402(2007)., PRB 77, 125131(2008).
[2] Yamamoto, Iwai et al., JPSJ77, 074709(2008).
[3] Kawakami, Iwai et al., PRL103, 066403 (2009).
[4] Kawakami, Iwai et al., PRL105, 246402(2010).
[5] Nakaya, Iwai et al., PRB81,15511(2010).
[6] K. Itoh, Iwai et al., PRL110, 10640(2013).
[7] K. Itoh, Iwai et al., PRB88, 125101(2013).
[8] H. Itoh, Iwai et al., APL104, 173302(2014).
[9] N. Tsuji, T. Oka, P. Werner, and H. Aoki, Phys. Rev. Lett. 106, 236401(2011).
[10] D. H. Dunlap and V. M. Kenkre, Phys. Rev. B34, 3625(1986).
[11] K. Nishioka and K. Yonemitsu, J. Phys. Soc. Jpn. 83, 024706 (2014).
世話人: 渡邊 浩 (内線:63377)
e-mail: hwata :at: issp.u-tokyo.ac.jp