Chen Yulin, Iyo Akira, Yang Wanli, Zhou Xingjiang, Lu Donghui, Eisaki Hiroshi, Devereaux Thomas P, Hussain Zahid, Shen Z-X
Department of Physics, Applied Physics, and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, California 94305, USA.
Phys Rev Lett. 2006 Dec 8;97(23):236401. doi: 10.1103/PhysRevLett.97.236401. Epub 2006 Dec 5.
We report the discovery of a self-doped multilayer high Tc superconductor Ba2Ca3Cu4O8F2 (F0234) which contains distinctly different superconducting gap magnitudes along its two Fermi-surface sheets. While formal valence counting would imply this material to be an undoped insulator, it is a self-doped superconductor with a Tc of 60 K, possessing simultaneously both electron- and hole-doped Fermi-surface sheets. Intriguingly, the Fermi-surface sheet characterized by the much larger gap is the electron-doped one, which has a shape disfavoring two electronic features considered to be important for the pairing mechanism: the van Hove singularity and the antiferromagnetic (pi/a, pi/a) scattering.
我们报告了一种自掺杂多层高温超导体Ba2Ca3Cu4O8F2（F0234）的发现，该超导体沿其两个费米面片具有明显不同的超导能隙大小。虽然形式上的化合价计算表明这种材料是未掺杂的绝缘体，但它是一种Tc为60 K的自掺杂超导体，同时拥有电子掺杂和空穴掺杂的费米面片。有趣的是，具有大得多的能隙的费米面片是电子掺杂的，其形状不利于两种被认为对配对机制很重要的电子特征：范霍夫奇点和反铁磁（π/a，π/a）散射。
