Dependence of upper critical field and pairing strength on doping in cuprates
Dependence of upper critical field and pairing strength on doping in cuprates
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DOI：
10.1126/science.1078422
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发表时间：
2003-01-03
期刊：
影响因子：
56.9
通讯作者：
Ong, NP
中科院分区：
文献类型：
--
作者：
Wang, YY;Ono, S;Ong, NP
我们已经确定了上临界场H-c2作为铋基铜酸盐中空穴浓度的函数，通过测量驱动温度梯度下涡流引起的电压（能量效应），磁场高达45特斯拉。我们发现，无论是单层铜酸盐还是双层铜酸盐，随着掺杂量的增加，H-c2都急剧下降。这一关系表明，库珀配对势与超流体密度随掺杂的变化趋势相反。对的相干长度xi(0)与光发射测量的间隙密切相关。我们讨论了理解临界温度T-c0的掺杂依赖性的意义。
We have determined the upper critical field H-c2 as a function of hole concentration in bismuth-based cuprates by measuring the voltage induced by vortex flow in a driving temperature gradient (the Nernst effect), in magnetic fields up to 45 tesla. We found that H-c2 decreased steeply as doping increased, in both single and bilayer cuprates. This relationship implies that the Cooper pairing potential displays a trend opposite to that of the superfluid density versus doping. The coherence length of the pairs xi(0) closely tracks the gap measured by photoemission. We discuss implications for understanding the doping dependence of the critical temperature T-c0.