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arXiv 0907.0647cond-mat.supr-concond-mat.str-el
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欠掺杂铜氧化物超导体正常态剩余超导电性的Specific-Heat测量

Specific-Heat Measurement of Residual Superconductivity in the Normal State of Underdoped Cuprate Superconductors

Hai-Hu Wen, Gang Mu, Huiqian Luo, Huan Yang, Lei Shan, Cong Ren, Peng Cheng, Jing Yan, Lei Fang

摘要:

我们测量了$Bi_2Sr_{2-x}La_xCuO_{6+δ}$单晶在宽掺杂区和宽温度区的比热随磁场和温度的变化关系。测定了与超导性有关的比热系数$γ_{sc}$和熵$S_{sc}$。发现$γ_{sc}$在$T_c$处有一个驼峰状的异常,并且表现为一个长尾,对于欠掺杂的样品,该长尾一直持续到正常态,但是对于重掺杂的样品,异常在$T_c$附近急剧结束。有趣的是,我们发现,与超导性相关的熵是大致守恒时,只有在正常状态下的长尾部分被考虑的欠掺杂的样品,表明T $_c$以上的剩余超导性。

英文摘要:

We have measured the magnetic field and temperature dependence of specific heat on $Bi_2Sr_{2-x}La_xCuO_{6+δ}$ single crystals in wide doping and temperature regions. The superconductivity related specific heat coefficient $γ_{sc}$ and entropy $S_{sc}$ are determined. It is found that $γ_{sc}$ has a hump-like anomaly at $T_c$ and behaves as a long tail which persists far into the normal state for the underdoped samples, but for the heavily overdoped samples the anomaly ends sharply just near $T_c$. Interestingly, we found that the entropy associated with superconductivity is roughly conserved when and only the long tail part in the normal state is taken into account for the underdoped samples, indicating the residual superconductivity above T$_c$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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