Lack of coupling between superconductivity and orthorhombic distortion in stoichiometric single-crystalline FeSe

作者:Boehmer A E; Hardy F; Eilers F; Ernst D; Adelmann P; Schweiss P; Wolf T; Meingast C
来源:Physical Review B, 2013, 87(18): 180505.
DOI:10.1103/PhysRevB.87.180505

摘要

The coupling between superconductivity and orthorhombic distortion is studied in vapor-grown FeSe single crystals using high-resolution thermal-expansion measurements. In contrast to the Ba122-based (Ba122) superconductors, we find that superconductivity does not reduce the orthorhombicity below T-c. Instead we find that superconductivity couples strongly to the in-plane area, which explains the large hydrostatic pressure effects. We discuss our results in light of the spin-nematic scenario and argue that FeSe has many features that are quite different from typical Fe-based superconductors.

  • 出版日期2013-5-23