Temperature dependence of clusters with attracting vortices in superconducting niobium studied by neutron scattering
Temperature dependence of clusters with attracting vortices in superconducting niobium studied by neutron scattering
复制标题
通过中子散射研究超导铌中吸引涡团簇的温度依赖性
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Annie Brûlet
中科院分区：
文献类型：
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作者：
Alain Pautrat;Annie Brûlet
我们用中子小角散射研究了超导铌样品的中间混合态。我们表明，这种状态是稳定的，通过一个序列，其中出现一个规则的涡旋晶格，然后在低温下消失之前与涡旋团共存。团簇中的涡旋具有恒定的周期性，而与所施加的场无关，并且表现出接近穿透深度的温度依赖性。团簇在高温极限消失。所有的结果都同意的解释涡吸引由于非局部效应，并表明钉扎的作用可以忽略不计。报道了Abrikosov涡晶格和涡团之间的相共存，显示了边界线的一阶性质。
We investigated the intermediate mixed state of a superconducting niobium sample using very small angle neutron scattering. We show that this state is stabilized through a sequence where a regular vortex lattice appears, which then coexists with vortex clusters before vanishing at low temperature. Vortices in clusters have a constant periodicity regardless of the applied field and exhibit a temperature dependence close to the one of the penetration depth. The clusters disappear in the high temperature limit. All the results agree with an explanation in terms of vortex attraction due to non-local effects and indicate a negligible role for pinning. Phase coexistence between the Abrikosov vortex lattice and vortex clusters is reported, showing the first-order nature of the boundary line.