Specific Heat vs Field in the 30 K Superconductor BaFe2(As0. 7P0. 3) 2
Specific Heat vs Field in the 30 K Superconductor BaFe2(As0. 7P0. 3) 2
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30 K 超导体 BaFe2(As0.7P0.3) 2 中的比热与场
DOI：
10.1103/physrevb.81.214507
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
and Y. Matsuda
中科院分区：
文献类型：
--
作者：
J. S. Kim;P. J. Hirschfeld;G. R. Stewart;S. Kasahara;T. Shibauchi;T. Terashima;and Y. Matsuda
我们报道了对特征良好的铁基超导体单晶的比热测量，这些测量来自同一批样品，之前的穿透深度、核磁共振和热导率测量在同一批晶体上观察到了高密度的低能激发，这些激发被用序参数节点解释。在我们测量的分辨率内，我们发现低温极限在场上是线性的，也就是说，我们没有发现与干净或肮脏极限中的节点准粒子有关的Volovik效应的证据。我们讨论了这一明显矛盾的可能原因，这可能是铁磷矿超导体中存在的多个费米面片的内在特征。
We report specific-heat measurements on well characterized single crystals of the Fe-based superconductor, from the same batch on which previous penetration depth, NMR, and thermal-conductivity measurements have observed a high density of low-energy excitations, which have been interpreted in terms of order-parameter nodes. Within the resolution of our measurements, the low-temperature limitingis found to be linear in field, i.e., we find no evidence for a Volovik effect associated with nodal quasiparticles in either the clean or dirty limit. We discuss possible reasons for this apparent contradiction, which may be an intrinsic feature of the multiple Fermi-surface sheets present in the iron pnictide superconductors.