EVIDENCE FOR STRIPE CORRELATIONS OF SPINS AND HOLES IN COPPER-OXIDE SUPERCONDUCTORS
EVIDENCE FOR STRIPE CORRELATIONS OF SPINS AND HOLES IN COPPER-OXIDE SUPERCONDUCTORS
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DOI：
10.1038/375561a0
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发表时间：
1995-06-15
期刊：
影响因子：
64.8
通讯作者：
UCHIDA, S
中科院分区：
文献类型：
--
作者：
TRANQUADA, JM;STERNLIEB, BJ;UCHIDA, S
与高温氧化铜超导体有关的长期未解之谜之一是，当空穴浓度x接近1/8时，La 2-xCuO 4（和某些相关化合物）的超导性受到反常抑制（1）。在这里，我们研究了这种效应与动力学二维自旋相关的可能性，与晶格不相称，这在La 2-xSrxCuO 4中通过中子散射观察到（2-4）。对不可通约性的一种可能解释涉及自旋和电荷的耦合动态调制，其中铜自旋的反铁磁“条纹”被周期性间隔的畴壁分开，空穴与畴壁分离（5-9）。最近在空穴掺杂的La_2NiO_4中观察到了这种类型的有序条纹相（参考文献10-12）。我们提出了来自中子衍射的证据，即在氧化铜材料La1.6-xNd0.4SrxCuO4（x=0.12）中，存在动态条纹相的静态类似物，并且与超导性的异常抑制有关（13，14）。因此，我们的结果提供了对“1/8”难题的解释，也支持了自旋和电荷密度的空间调制与铜氧化物中的超导性有关的建议。
ONE Of the long-standing mysteries associated with the high-temperature copper oxide superconductors concerns the anomalous suppression(1) of superconductivity in La2-xBaxCuO4 (and certain related compounds) when the hole concentration x is near 1/8. Here we examine the possibility that this effect is related to dynamical two-dimensional spin correlations, incommensurate with the crystal lattice, that have been observed in La2-xSrxCuO4 by neutron scattering(2-4). A possible explanation for the incommensurability involves a coupled, dynamical modulation of spin and charge in which antiferromagnetic 'stripes' of copper spins are separated by periodically spaced domain walls to which the holes segregate(5-9). An ordered stripe phase of this type has recently been observed in hole-doped La2NiO4 (refs 10-12). We present evidence from neutron diffraction that in the copper oxide material La1.6-xNd0.4SrxCuO4, with x=0.12, a static analogue of the dynamical stripe phase is present, and is associated with an anomalous suppression of superconductivity(13,14). Our results thus provide an explanation of the '1/8' conundrum, and also support the suggestion(15) that spatial modulations of spin and charge density are related to superconductivity in the copper oxides.