Multigap nodeless superconductivity in FeSe x : Evidence from quasiparticle heat transport
Multigap nodeless superconductivity in FeSe x : Evidence from quasiparticle heat transport
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DOI：
10.1103/physrevb.80.024518
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发表时间：
2009-07
影响因子：
3.7
通讯作者：
J. Dong;T. Y. Guan;S. Zhou;X. Qiu;L. Ding;Chun Zhang;U. Patel;Zhili Xiao;S. Y. Li
中科院分区：
文献类型：
--
作者：
J. Dong;T. Y. Guan;S. Zhou;X. Qiu;L. Ding;Chun Zhang;U. Patel;Zhili Xiao;S. Y. Li
The in-plane thermal conductivity $\ensuremath{\kappa}$ of the iron selenide superconductor ${\text{FeSe}}_{x}$ $({T}_{c}=8.8\text{ }\text{K})$ was measured down to 120 mK and up to 14.5 T $(\ensuremath{\simeq}3/4{H}_{{c}_{2}})$. In zero field, the residual linear term ${\ensuremath{\kappa}}_{0}/T$ at $T\ensuremath{\rightarrow}0$ is only about $16\text{ }\ensuremath{\mu}\text{W}\text{ }{\text{K}}^{\ensuremath{-}2}\text{ }{\text{cm}}^{\ensuremath{-}1}$, less than 4% of its normal-state value. Such a small ${\ensuremath{\kappa}}_{0}/T$ does not support the existence of nodes in the superconducting gap. More importantly, the field dependence of ${\ensuremath{\kappa}}_{0}/T$ in ${\text{FeSe}}_{x}$ is very similar to that in ${\text{NbSe}}_{2}$, a typical multigap $s$-wave superconductor. We consider our data as strong evidence for multigap nodeless (at least in $ab$ plane) superconductivity in ${\text{FeSe}}_{x}$. This kind of superconducting gap structure may be generic for all Fe-based superconductors.
The in-plane thermal conductivity $\ensuremath{\kappa}$ of the iron selenide superconductor ${\text{FeSe}}_{x}$ $({T}_{c}=8.8\text{ }\text{K})$ was measured down to 120 mK and up to 14.5 T $(\ensuremath{\simeq}3/4{H}_{{c}_{2}})$. In zero field, the residual linear term ${\ensuremath{\kappa}}_{0}/T$ at $T\ensuremath{\rightarrow}0$ is only about $16\text{ }\ensuremath{\mu}\text{W}\text{ }{\text{K}}^{\ensuremath{-}2}\text{ }{\text{cm}}^{\ensuremath{-}1}$, less than 4% of its normal-state value. Such a small ${\ensuremath{\kappa}}_{0}/T$ does not support the existence of nodes in the superconducting gap. More importantly, the field dependence of ${\ensuremath{\kappa}}_{0}/T$ in ${\text{FeSe}}_{x}$ is very similar to that in ${\text{NbSe}}_{2}$, a typical multigap $s$-wave superconductor. We consider our data as strong evidence for multigap nodeless (at least in $ab$ plane) superconductivity in ${\text{FeSe}}_{x}$. This kind of superconducting gap structure may be generic for all Fe-based superconductors.