Enhancement of the superconducting transition temperature of La2-xSrxCuO4 bilayers: role of pairing and phase stiffness.
Enhancement of the superconducting transition temperature of La2-xSrxCuO4 bilayers: role of pairing and phase stiffness.
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DOI：
10.1103/physrevlett.101.057005
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发表时间：
2008-05
影响因子：
8.6
通讯作者：
O. Yuli;I. Asulin;O. Millo;D. Orgad;L. Iomin;G. Koren
中科院分区：
文献类型：
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作者：
O. Yuli;I. Asulin;O. Millo;D. Orgad;L. Iomin;G. Koren
发现在低掺杂La（2-x）Sr（x）CuO（4）薄膜上覆盖一层重掺杂La（1.65）Sr（0.35）CuO（4）金属层的双层膜的超导转变温度T（c）相对于裸低掺杂薄膜的T（c）有所增加。当x=0.12时，达到最高的T（c），接近“异常”1/8掺杂水平，并且超过最佳掺杂的裸膜的T（c）。我们的数据表明，增强的超导电性仅限于层之间的界面。我们将这种效应归因于低掺杂层中的高配对尺度与由过掺杂膜引起的增强的相刚度的组合。
The superconducting transition temperature T(c) of bilayers comprising underdoped La(2-x)Sr(x)CuO(4) films capped by a thin heavily overdoped metallic La(1.65)Sr(0.35)CuO(4) layer, is found to increase with respect to T(c) of the bare underdoped films. The highest T(c) is achieved for x=0.12, close to the "anomalous" 1/8 doping level, and exceeds that of the optimally doped bare film. Our data suggest that the enhanced superconductivity is confined to the interface between the layers. We attribute the effect to a combination of the high pairing scale in the underdoped layer with an enhanced phase stiffness induced by the overdoped film.