Optical Modulation of Effective On-Site Coulomb Energy for the Mott Transition in an Organic Dimer Insulator
Optical Modulation of Effective On-Site Coulomb Energy for the Mott Transition in an Organic Dimer Insulator
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DOI：
10.1103/physrevlett.103.066403
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发表时间：
2009-08-07
影响因子：
8.6
通讯作者：
Kobayashi, N.
中科院分区：
文献类型：
--
作者：
Kawakami, Y.;Iwai, S.;Kobayashi, N.
我们报道了二聚体（U-二聚体）上的有效现场库仑能量U的光学调制，以实现kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br中的Mott绝缘体到金属的转变，并通过泵浦探针光谱进行了研究。在二聚体激发下，u -二聚体的分子位移是光诱导的。这种金属化机制与先前报道的光掺杂型机制有很大不同。相比之下，通过光掺杂机制检测到间二聚体激发的更快转变。在Mott过渡线的临界端点附近，还观察到由u -二聚体调制引起的金属畴壁振荡。
We report an optical modulation of the effective on-site Coulomb energy U on a dimer (U-dimer) for achieving the Mott insulator-to-metal transition in kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br, as investigated by pump-probe spectroscopy. A reduction of U-dimer is optically induced by molecule displacement in the dimer under intradimer excitation. The mechanism of this metallization differs greatly from the photodoping-type mechanism reported previously. In contrast, a faster transition via the photodoping mechanism is detected for interdimer excitation. A metallic-domain-wall oscillation originating from the modulation of U-dimer was also observed near the critical end point of the Mott transition line.