Lanzara A, Bogdanov P V, Zhou X J, Kellar S A, Feng D L, Lu E D, Yoshida T, Eisaki H, Fujimori A, Kishio K, Shimoyama J I, Noda T, Uchida S, Hussain Z, Shen Z X
Department of Physics, Applied Physics and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, USA.
Nature. 2001 Aug 2;412(6846):510-4. doi: 10.1038/35087518.
Coupling between electrons and phonons (lattice vibrations) drives the formation of the electron pairs responsible for conventional superconductivity. The lack of direct evidence for electron-phonon coupling in the electron dynamics of the high-transition-temperature superconductors has driven an intensive search for an alternative mechanism. A coupling of an electron with a phonon would result in an abrupt change of its velocity and scattering rate near the phonon energy. Here we use angle-resolved photoemission spectroscopy to probe electron dynamics-velocity and scattering rate-for three different families of copper oxide superconductors. We see in all of these materials an abrupt change of electron velocity at 50-80 meV, which we cannot explain by any known process other than to invoke coupling with the phonons associated with the movement of the oxygen atoms. This suggests that electron-phonon coupling strongly influences the electron dynamics in the high-temperature superconductors, and must therefore be included in any microscopic theory of superconductivity.
电子与声子（晶格振动）之间的耦合驱动了负责传统超导性的电子对的形成。在高温超导材料的电子动力学中，缺乏电子 - 声子耦合的直接证据促使人们密集地寻找替代机制。电子与声子的耦合会导致其速度和散射率在声子能量附近发生突然变化。在这里，我们使用角分辨光电子能谱来探测三种不同系列的氧化铜超导体的电子动力学——速度和散射率。我们在所有这些材料中都看到电子速度在50 - 80毫电子伏特处发生突然变化，除了援引与氧原子运动相关的声子耦合外，我们无法用任何已知过程来解释这一现象。这表明电子 - 声子耦合强烈影响高温超导体中的电子动力学，因此在任何超导微观理论中都必须考虑这一点。
