Photoinduced insulator-metal transition and nonlinear optical response of correlated electrons – a DMFT analysis
Photoinduced insulator-metal transition and nonlinear optical response of correlated electrons – a DMFT analysis
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光致绝缘体-金属转变和相关电子的非线性光学响应 - DMFT 分析
DOI：
10.1088/1742-6596/148/1/012058
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Hideo Aoki
中科院分区：
文献类型：
--
作者：
N. Tsuji;Takashi Oka;Hideo Aoki
本文将动力学平均场理论推广到非平衡系统，研究了Falicov-Kimball模型中的光致绝缘体-金属相变。当泵浦光的光子能量为Ω/cm（U：相互作用强度）时，在电导谱中发现了一个Drude峰，这表明体系被驱动到了金属态。在过渡期间，带隙不崩溃，而分布函数表现出远离费米分布的非单调行为。这表明这种转变不能由加热效应来解释，而是由光载流子的产生来解释。
We investigate a photoinduced insulator-metal transition in the Falicov-Kimball model with the dynamical mean-field theory (DMFT) extended to nonequilibrium systems in periodic modulations in time. When the photon energy of the pump light is Ω≈ (U: the interaction strength), a Drude-like peak is found to grow in the optical conductivity spectrum, which is an evidence that the system is driven into a metallic state. During the transition, the band gap does not collapse, whereas the distribution function exhibits a non-monotonic behaviour away from the Fermi distribution. This indicates that the transition cannot be accounted for by heating effects, but creation of photo-carriers is responsible.