Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Straße 1, 76131 Karlsruhe, Germany.
Max-Planck Institut für Mikrostrukturphysik, Weinberg 2, 06120 Halle, Germany.
Phys Rev Lett. 2015 Jan 30;114(4):047002. doi: 10.1103/PhysRevLett.114.047002. Epub 2015 Jan 29.
Inelastic tunneling spectroscopy of Pb islands on Cu(111) obtained by scanning tunneling microscopy below 1 K provides a direct access to the local Eliashberg function of the islands with high energy resolution. The Eliashberg function describes the electron-phonon interaction causing conventional superconductivity. The measured Eliashberg function strongly depends on the local thickness of the Pb nanostructures and shows a sharp maximum when quantum well states of the Pb islands come close to the Fermi energy. Ab initio calculations reveal that this is related to enhanced electron-phonon coupling at these thicknesses.
通过在 1 K 以下进行扫描隧道显微镜实验，对 Cu(111) 上 Pb 岛的非弹性隧道谱进行研究，为获得具有高能量分辨率的局域 Eliashberg 函数提供了一种直接的方法。Eliashberg 函数描述了导致传统超导性的电子-声子相互作用。所测量的 Eliashberg 函数强烈依赖于 Pb 纳米结构的局域厚度，并且当 Pb 岛的量子阱态接近费米能时，会出现尖锐的最大值。从头计算表明，这与这些厚度下增强的电子-声子耦合有关。
