Multiband superconductivity and nanoscale inhomogeneity at oxide interfaces
Multiband superconductivity and nanoscale inhomogeneity at oxide interfaces
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DOI：
10.1103/physrevb.88.020504
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发表时间：
2013-07-22
影响因子：
3.7
通讯作者：
Grilli, M.
中科院分区：
文献类型：
--
作者：
Caprara, S.;Biscaras, J.;Grilli, M.
当通过选通调整载流子密度时，LaTiO 3/SrTiO 3或LaAlO 3/SrTiO 3氧化物界面处的二维电子气变为超导。测量的电阻和超流密度揭示了一种非均匀的超导性，这种超导性是由嵌入在非超导基质中的具有随机分布临界温度的超导“水坑”的非导电结构的渗流引起的。在超导性与高迁移率载流子的出现有关的证据之后，我们通过弱耦合BCS方案中的多带系统来模拟熔池内超导性。微观参数，通过拟合的传输数据与一个简化模型提取，产生一致的描述的平均intrapudle临界温度和超流密度的载流子密度的依赖性。
The two-dimensional electron gas at the LaTiO3/SrTiO3 or LaAlO3/SrTiO3 oxide interfaces becomes superconducting when the carrier density is tuned by gating. The measured resistance and superfluid density reveal an inhomogeneous superconductivity resulting from percolation of filamentary structures of superconducting "puddles" with randomly distributed critical temperatures, embedded in a nonsuperconducting matrix. Following the evidence that superconductivity is related to the appearance of high-mobility carriers, we model intrapuddle superconductivity by a multiband system within a weak coupling BCS scheme. The microscopic parameters, extracted by fitting the transport data with a percolative model, yield a consistent description of the dependence of the average intrapuddle critical temperature and superfluid density on the carrier density.