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arXiv 1301.1845cond-mat.supr-con
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NbS $_{2}$中的面内磁穿透深度

In-plane magnetic penetration depth in NbS$_{2}$

Pascale Diener, Maxime Leroux, Laurent Cario, Thierry Klein, Pierre Rodiere

摘要:

本文报道了2 H-NbS $_2$单晶的面内磁穿透深度($λ_{ab}$)和第一穿透场($H_f\propto 1/λ_{ab}^2(T)$对$H\|c$)的温度依赖性。在$λ_{ab}$(T)中观察到明显的指数温度关系,表明存在完全开放的超导能隙。该化合物是唯一不产生电荷密度波(CDW)的超导2 H-二硫属化物。然而,如先前在2 H-NbSe $_2$中观察到的,该间隙($Δ_{1}=1.1\, k_{B}T_{c}$)显著小于标准BCS弱耦合值。在较高的温度下,必须引入较大的能隙($Δ_{2}=1.8\, k_{B}T_{c}$)来描述与双能隙模型兼容的数据。超导间隙是非常相似的,因此在NbS $_2$和NbSe $_2$,我们在这里表明,他们都打开在强耦合的Nb管片独立的CDW的存在与否。

英文摘要:

We report on the temperature dependence of the in plane magnetic penetration depth ($λ_{ab}$) and first penetration field ($H_f\propto 1/λ_{ab}^2(T)$ for $H\|c$) in 2H-NbS$_2$ single crystals. An exponential temperature dependence is clearly observed in $λ_{ab}$(T) at low temperature, signing the presence of a fully open superconducting gap. This compound is the only superconducting 2H-dichalcogenide which does not develop a charge density wave (CDW). However as previously observed in 2H-NbSe$_2$, this gap ($Δ_{1}=1.1\, k_{B}T_{c}$) is significantly smaller than the standard BCS weak coupling value. At higher temperature, a larger gap ($Δ_{2}=1.8\, k_{B}T_{c}$) has to be introduced to describe the data which are compatible with a two gap model. The superconducting gaps are hence very similar in NbS$_2$ and NbSe$_2$ and we show here that both of them open in the strongly coupled Nb tubular sheets independently of the presence of a CDW or not.

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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