Nonequilibrium steady states in correlated electron systems — Photoinduced insulator-metal transition and optical response
Nonequilibrium steady states in correlated electron systems — Photoinduced insulator-metal transition and optical response
复制标题
相关电子系统中的非平衡稳态——光致绝缘体-金属转变和光学响应
DOI：
10.1088/1742-6596/200/1/012212
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
H. Aoki
中科院分区：
文献类型：
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作者：
N. Tsuji;T. Oka;H. Aoki
为了揭示光致绝缘体-金属转变的本质，我们表明，通过 Floquet 方法与非平衡动态平均场理论相结合，可以对受外部交流电场影响的 Falicov-Kimball 模型进行精确分析。如果引入特定热浴模型中的耗散，则可以确定泵浦光照射期间出现的非平衡稳态。这使我们能够预测在光导率中应该观察到光激发稳态的新特征，即低能区的负权重（增益）和泵浦光的光子能量周围的倾斜结构。特别强调耗散的作用，为此我们详细阐述了稳态对耗散强度和热浴温度的依赖性。
To reveal the nature of the photoinduced insulator-metal transition, we show that an exact analysis of the Falicov-Kimball model subject to external ac electric fields becomes possible with Floquet's method combined with the nonequilibrium dynamical mean-field theory. The nonequilibrium steady state that appears during irradiation of a pump light is shown to be determined if the dissipation in a certain heat-bath model is introduced. This has enabled us to predict that novel features characteristic of the photoexcited steady states, i.e., negative weight (gain) in the low-energy region and dip structures around the photon energy of the pump light, should be observed in the optical conductivity. Special emphasis is put on the role of dissipation, for which we elaborate the dependence of the steady state on the strength of dissipation and the temperature of the heat bath.