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arXiv 1303.4658cond-mat.supr-con
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TlNi2Se2单晶中重电子的多带超导电性

Multiband Superconductivity of Heavy Electrons in TlNi2Se2 single crystal

Hangdong Wang, Chiheng Dong, Qianhui Mao, Rajwali Khan, Xi Zhou, Zhenxia Li, Bin Chen, Jinhu Yang, Qiping Su, Minghu Fang

摘要:

TlNi $_2$ Se $_2$在T $_C$ =3.7 K时首次观察到超导性,并由正常态电子比热和上临界场H_ ${C2}$(T)推断出,似乎涉及有效质量为$m^*$ =14 $\sim$ 20 $m_b$的重电子。虽然零场电子比热数据$C_{es}(T)$在低温(T < 1/4 T $_C$)下可以用能隙BCS模型拟合,表明TlNi $_2$ Se $_2$是一个完全能隙的超导体,但双能隙BCS模型对所有低于$T_C$的$C_{es}(T)$数据的拟合最好。还发现混合态的电子比热系数$γ_N(H)$表现出\textit{H} $^{1/2}$行为,这也在一些\textit{s}波超导体中观察到,尽管曾经被认为是\textit{d}波超导体的共同特征。总之,这些结果表明,TlNiPDMATHABMMSePDMATHABMM作为TlFePDMATHABMZSePDMATHABMM超导体的非磁性类似物,是重电子系的多带超导体。

英文摘要:

Superconductivity has been first observed in TlNi$_2$Se$_2$ at T$_C$=3.7 K and appears to involve heavy electrons with an effective mass $m^*$=14$\sim$20 $m_b$, as inferred from the normal state electronic specific heat and the upper critical field, H_${C2}$(T). Although the zero-field electronic specific heat data, $C_{es}(T)$, in low temperatures (T < 1/4 T$_C$) can be fitted with a gap BCS model, indicating that TlNi$_2$Se$_2$ is a fully gapped superconductor, the two-gap BCS model presents the best fit to all the $C_{es}(T)$ data below $T_C$. It is also found that the electronic specific heat coefficient in the mixed state, $γ_N(H)$, exhibits a \textit{H}$^{1/2}$ behavior, which was also observed in some \textit{s}-wave superconductors, although once considered as a common feature of the \textit{d}-wave superconductors. Anyway, these results indicate that TlNi$_2$Se$_2$, as a non-magnetic analogue of TlFe$_x$Se$_2$ superconductor, is a multiband superconductor of heavy electron system.

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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