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arXiv 0706.2612cond-mat.mes-hall
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介观体系中的费米边缘奇异性:II。光吸收光谱

Fermi Edge Singularities in the Mesoscopic Regime: II. Photo-absorption Spectra

M. Hentschel, D. Ullmo, H. U. Baranger

摘要:

我们研究了一般介观系统如量子点或纳米颗粒的光吸收谱中的费米边奇异性。我们预测偏离宏观金属的行为,并提出实验装置观察这些影响。该理论是基于一个本地化的模型,或秩一,扰动所造成的(核心)后留下的光激发电子进入导带的孔。光吸收谱是两个多体响应、Anderson正交性突变和Mahan-Nozieres-DeDominant贡献之间竞争的结果。这两种机制都依赖于系统的大小,通过粒子的数量,更重要的是,由介观样品的相干特性产生的波动。后者导致偶极矩阵元素的修改,并触发我们的关键结果之一:通常在金属中发现的圆形K边将变成平均在介观制度中的(轻微)峰边。我们详细地考虑了由中心空穴产生的“束缚态”的影响。

英文摘要:

We study Fermi edge singularities in photo-absorption spectra of generic mesoscopic systems such as quantum dots or nanoparticles. We predict deviations from macroscopic-metallic behavior and propose experimental setups for the observation of these effects. The theory is based on the model of a localized, or rank one, perturbation caused by the (core) hole left behind after the photo-excitation of an electron into the conduction band. The photo-absorption spectra result from the competition between two many-body responses, Anderson's orthogonality catastrophe and the Mahan-Nozieres-DeDominicis contribution. Both mechanisms depend on the system size through the number of particles and, more importantly, fluctuations produced by the coherence characteristic of mesoscopic samples. The latter lead to a modification of the dipole matrix element and trigger one of our key results: a rounded K-edge typically found in metals will turn into a (slightly) peaked edge on average in the mesoscopic regime. We consider in detail the effect of the "bound state" produced by the core hole.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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