Ultrafast dynamics of Mott state quench and formation in strongly correlated BEDT-TTF molecular conductors observed by three-pulse pump probe spectroscopy
Ultrafast dynamics of Mott state quench and formation in strongly correlated BEDT-TTF molecular conductors observed by three-pulse pump probe spectroscopy
复制标题
三脉冲泵浦探针光谱观察强相关BEDT-TTF分子导体中莫特态猝灭和形成的超快动力学
DOI：
10.1103/physrevb.104.115152
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发表时间：
2021
影响因子：
3.7
通讯作者：
D. Mihailovic and T. Mertelj
中科院分区：
文献类型：
--
作者：
S. Tsuchiya;H. Taniguchi;J. Yamada;Y. Toda;D. Mihailovic and T. Mertelj
我们利用三脉冲飞秒光谱研究了莫特绝缘体和超导体中莫特态的淬灭和实时形成以及光激发载流子弛豫动力学，其中BEDT-TTF是双(乙撑二硫)四硫富瓦烯。在这两种盐中，我们发现在强近红外脉冲猝灭后瞬态反射率幅度随着时间的推移逐渐恢复，但其弛豫时间始终几乎恒定。这表明在-Cl中，电荷激发的能隙被每个二聚体仅%的光生载流子填充而不是封闭。随着费米能附近带隙内光电掺杂诱导态的消失，莫特态在几皮秒的时间尺度上重新形成。 In-Br 观察到与 in-Cl 类似的行为，并将其归因于无序诱导的相分离莫特绝缘区域。
We investigate the quench and real-time formation of the Mott state and photoexcited carrier relaxation dynamics in the Mott insulatorand the superconductorusing three-pulse femtosecond optical spectroscopy, where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene. In both salts, we find that transient reflectivity amplitude gradually recovers with time after strong near-infrared pulse quench, but its relaxation time is nearly constant throughout. This indicates that in-Cl, the energy gap for charge excitations isfilledrather than closed by photoinduced carriers of only% per dimer. The Mott state is re-formed on a few-picosecond timescale with the disappearance of the in-gap photodoping-induced states near the Fermi energy. In-Br, a behavior similar to that in-Cl is observed and attributed to the disorder-induced phase-separated Mott insulating regions.