Ferromagnetic order beyond the superconducting dome in a cuprate superconductor
Ferromagnetic order beyond the superconducting dome in a cuprate superconductor
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DOI：
10.1126/science.aax1581
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发表时间：
2020-05-01
期刊：
影响因子：
56.9
通讯作者：
Greene, Richard L.
中科院分区：
文献类型：
--
作者：
Sarkar, Tarapada;Wei, D. S.;Greene, Richard L.
根据传统的观点，铜氧化物高温超导体的非凡性能来自于掺杂强相关的反铁磁绝缘体。高度过掺杂的铜氧化物-其掺杂超出了超导性的圆顶-被认为是传统的费米液体金属。我们报告的巡游铁磁秩序的出现低于4开尔文的电子掺杂的La 2-x，CexCuO 4（LCCO）的薄膜中的超导圆顶掺杂。这种铁磁有序的存在是由负的、各向异性的和滞后的磁阻、滞后磁化和极性克尔效应证明的，所有这些都是金属中巡回铁磁性的标准特征。这一令人惊讶的结果表明，过掺杂的铜酸盐受到电子关联的强烈影响。
According to conventional wisdom, the extraordinary properties of the cuprate high-temperature superconductors arise from doping a strongly correlated antiferromagnetic insulator. The highly overdoped cuprates-whose doping lies beyond the dome of superconductivity-are considered to be conventional Fermi liquid metals. We report the emergence of itinerant ferromagnetic order below 4 kelvin for doping beyond the superconducting dome in thin films of electron-doped La2-x,CexCuO4 (LCCO). The existence of this ferromagnetic order is evidenced by negative, anisotropic, and hysteretic magnetoresistance, hysteretic magnetization, and the polar Kerr effect all of which are standard signatures of itinerant ferromagnetism in metals. This surprising result suggests that the overdoped cuprates are strongly influenced by electron correlations.