论文标题
超导体中的深色Andreev状态
Dark Andreev States in Superconductors
论文作者
论文摘要
超导性的常规Bardeen-Cooper-Schrieffer（BCS）模型假定频率独立的顺序参数，该参数允许对超导状态的相对简单描述。特别是，它的激发光谱很容易遵循Bogoliubov-de-gennes（BDG）方程。对超导体的更现实的描述是Migdal-Eliashberg理论，其中配对相互作用，顺序参数和电子自我能源非常依赖于频率。这项工作将这些语音介导的超导的成分与标准BDG方法结合在一起。令人惊讶的是，我们发现了定性的新特征，例如在靠近Debye Energy的能量的准粒子光谱中出现了阴影超导间隙。我们展示了这些功能如何在标准隧道实验中展现出来。最后，我们还预测了其他高能结合状态的存在，我们将其称为“黑暗的Andreev国家”。
The conventional Bardeen-Cooper-Schrieffer (BCS) model of superconductivity assumes a frequency-independent order parameter, which allows a relatively simple description of the superconducting state. In particular, its excitation spectrum readily follows from the Bogoliubov-de-Gennes (BdG) equations. A more realistic description of a superconductor is the Migdal-Eliashberg theory, where the pairing interaction, the order parameter, and electronic self-energy are strongly frequency dependent. This work combines these ingredients of phonon-mediated superconductivity with the standard BdG approach. Surprisingly, we find qualitatively new features such as the emergence of a shadow superconducting gap in the quasiparticle spectrum at energies close to the Debye energy. We show how these features reveal themselves in standard tunneling experiments. Finally, we also predict the existence of additional high-energy bound states, which we dub "dark Andreev states."
