Electronic origin of high-temperature superconductivity in single-layer FeSe superconductor
Electronic origin of high-temperature superconductivity in single-layer FeSe superconductor
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DOI：
10.1038/ncomms1946
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发表时间：
2012-07-01
影响因子：
16.6
通讯作者：
Zhou, X. J.
中科院分区：
文献类型：
--
作者：
Liu, Defa;Zhang, Wenhao;Zhou, X. J.
近年来，铁基化合物中高温超导性的发现引起了人们的广泛关注。如何进一步提高超导转变温度（T-c）以及如何理解超导机理是当前铁基超导体研究面临的两个突出问题。因此，单层FeSe中高t -c超导性的最新报道既令人惊讶又意义重大。本文对单层FeSe超导体的电子结构和超导间隙进行了研究。它的费米表面与其他铁基超导体不同，仅由靠近区域角落的电子状口袋组成，而在区域中心周围没有任何费米表面的迹象。在这个严格的二维体系中观察到几乎各向同性的超导隙。超导间隙的温度依赖性给出了类似于55k的转变温度T-c。这些结果建立了一个明确的案例，即这样一个简单的电子结构与铁基超导体中的高t -c超导性兼容。
The recent discovery of high-temperature superconductivity in iron-based compounds has attracted much attention. How to further increase the superconducting transition temperature (T-c) and how to understand the superconductivity mechanism are two prominent issues facing the current study of iron-based superconductors. The latest report of high-T-c superconductivity in a single-layer FeSe is therefore both surprising and significant. Here we present investigations of the electronic structure and superconducting gap of the single-layer FeSe superconductor. Its Fermi surface is distinct from other iron-based superconductors, consisting only of electron-like pockets near the zone corner without indication of any Fermi surface around the zone centre. Nearly isotropic superconducting gap is observed in this strictly two-dimensional system. The temperature dependence of the superconducting gap gives a transition temperature T-c similar to 55 K. These results have established a clear case that such a simple electronic structure is compatible with high-T-c superconductivity in iron-based superconductors.