Breakdown of Fermi-liquid theory in a copper-oxide superconductor
Breakdown of Fermi-liquid theory in a copper-oxide superconductor
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DOI：
10.1038/414711a
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发表时间：
2001-12
期刊：
影响因子：
64.8
通讯作者：
R. W. Hill;C. Proust;C. Proust;L. Taillefer;P. Fournier;P. Fournier;R. L. Greene
中科院分区：
文献类型：
--
作者：
R. W. Hill;C. Proust;C. Proust;L. Taillefer;P. Fournier;P. Fournier;R. L. Greene
朗道的费米-液体理论很好地描述了固体中电子的行为，该理论预测，尽管金属中的电子相互作用，但它们仍然可以被视为定义良好的费米子，即“准粒子”。在低温下，准粒子传输热量的能力严格取决于它们传输电荷的能力，正如一个被称为Wiedemann-Franz定律的普遍关系所描述的那样，迄今为止还没有发现违反该定律的物质。高温超导体长期以来一直被认为不属于费米液体理论的范畴，因为一些反常的性质表明，但这还没有得到确凿的证明。本文报道了一种铜氧化物超导体（Pr,Ce）2CuO4在正常状态下对Wiedemann-Franz定律的实验测试，结果表明在这种材料中携带热量的元素激发不是费米子。这是高温超导体中费米液体理论瓦解的有力证据。
The behaviour of electrons in solids is well described by Landau's Fermi-liquid theory, which predicts that although electrons in a metal interact, they can still be treated as well defined fermions, which are called ‘quasiparticles’. At low temperatures, the ability of quasiparticles to transport heat is given strictly by their ability to transport charge, as described by a universal relation known as the Wiedemann–Franz law, which hitherto no material has been known to violate. High-temperature superconductors have long been thought to fall outside the realm of Fermi-liquid theory, as suggested by several anomalous properties, but this has yet to be shown conclusively. Here we report an experimental test of the Wiedemann–Franz law in the normal state of a copper-oxide superconductor, (Pr,Ce)2CuO4, which reveals that the elementary excitations that carry heat in this material are not fermions. This is compelling evidence for the breakdown of Fermi-liquid theory in high-temperature superconductors.