Various technical developments have extended the potential of angle-resolved photoemission spectroscopy (ARPES) tremendously over the last 20 years. In particular improved momentum, energy, and spin resolution as well as the use of photon energies from a few eV up to several keV make ARPES a rather unique tool to investigate the electronic properties of solids and surfaces. With our work we present a generalization of the state-of-the-art description of the photoemission process, the so-called one-step model that describes excitation, transport to the surface, and escape into the vacuum in a coherent way. In particular, we present a theoretical description of temperature-dependent ARPES with a special emphasis on spin fluctuations. Finite-temperature effects are included within the so-called alloy analogy model which is based on the coherent potential approximation, and this method allows us to describe uncorrelated lattice vibrations in combination with spin fluctuations quantitatively on the same level of accuracy. To demonstrate the applicability of our approach a corresponding numerical analysis has been applied to spin- and angle-resolved photoemission of Fe(100) at finite temperatures.

中文翻译：

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有限温度下光发射的一步模型：Fe（001）的自旋涨落

在过去的20年中，各种技术发展极大地扩展了角度分辨光发射光谱（ARPES）的潜力。特别是改善的动量，能量和自旋分辨率，以及从几eV到几keV的光子能量的使用，使ARPES成为研究固体和表面电子特性的相当独特的工具。通过我们的工作，我们对光发射过程的最新描述进行了概括，即所谓的一步模型，该模型描述了激发，向表面传输以及以连贯方式逃逸到真空中。特别是，我们提出了与温度有关的ARPES的理论描述，并特别强调了自旋波动。有限温度效应包含在基于相干势近似的所谓合金类比模型中，该方法使我们能够以相同的精确度定量描述不相关的晶格振动以及自旋涨落。为了证明我们方法的适用性，在有限温度下，对Fe（100）的自旋和角分辨光发射进行了相应的数值分析。