块状超导性和高压下铁基超导体 FeSe 中涨落的作用。

Bulk Superconductivity and Role of Fluctuations in the Iron-Based Superconductor FeSe at High Pressures.

机构信息

Ames Laboratory, U.S. Department of Energy, Iowa State University, Ames, Iowa 50011, USA.

Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.

出版信息

Phys Rev Lett. 2019 Oct 18;123(16):167002. doi: 10.1103/PhysRevLett.123.167002.

DOI:10.1103/PhysRevLett.123.167002

PMID:31702365

Abstract

The iron-based superconductor FeSe offers a unique possibility to study the interplay of superconductivity with purely nematic as well magnetic-nematic order by pressure (p) tuning. By measuring specific heat under p up to 2.36 GPa, we study the multiple phases in FeSe using a thermodynamic probe. We conclude that superconductivity is bulk across the entire p range and competes with magnetism. In addition, whenever magnetism is present, fluctuations exist over a wide temperature range above both the bulk superconducting and the magnetic transitions. Whereas the magnetic fluctuations are likely temporal, the superconducting fluctuations may be either temporal or spatial. These observations highlight similarities between FeSe and underdoped cuprate superconductors.

摘要

铁基超导体 FeSe 为通过压力（p）调谐研究超导与纯向列相以及磁向列序的相互作用提供了独特的可能性。通过在高达 2.36 GPa 的压力下测量比热，我们使用热力学探针研究了 FeSe 中的多种相。我们得出结论，超导性在整个 p 范围内是整体的，并与磁性竞争。此外，只要存在磁性，在高于体超导转变和磁性转变的宽温度范围内就存在波动。虽然磁性波动可能是暂时的，但超导波动可能是暂时的或空间的。这些观察结果突出了 FeSe 和欠掺杂铜酸盐超导体之间的相似性。