Doping dependence of the critical fluctuation regime in the Fe-based superconductor Ba1-xKxFe2As2

被引：5

作者：

Hou, Jianqiang ^{[1
]}

Burger, Philipp ^{[2
]}

Mak, Huen Kit ^{[1
]}

Hardy, Frederic ^{[2
]}

Wolf, Thomas ^{[2
]}

Meingast, Christoph ^{[2
]}

Lortz, Rolf ^{[1
]}

机构：

[1] Hong Kong Univ Sci & Technol, Dept Phys, Kowloon, Hong Kong, Peoples R China

[2] Karlsruhe Inst Technol, Inst Solid State Phys, D-76021 Karlsruhe, Germany

来源：

PHYSICAL REVIEW B | 2015年 / 92卷 / 06期

关键词：

YBA2CU3O7-DELTA SINGLE-CRYSTALS; MAGNETIC-FIELD; HEAT; PSEUDOGAP; HE-4; LINE;

D O I：

10.1103/PhysRevB.92.064502

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We investigate the importance of superconducting order parameter fluctuations in the 122 family of Fe-based superconductors, using high-resolution specific heat and thermal expansion data of various Ba1-xKxFe2As2 single crystals covering a large range of the phase diagram from the strongly underdoped to the overdoped regime. By applying scaling relations of the 3d-XY and the 3d-lowest-Landau-level (3d-LLL) fluctuation models to data measured in different magnetic fields, we demonstrate that a strong increase of the critical fluctuation regime is responsible for the transition broadening in magnetic fields, which is a direct consequence of a magnetic-field-induced finite-size effect due to a reduction of the effective dimensionality by a decreasing magnetic length scale related to the mean vortex separation and the confinement of quasiparticles in LLL. The fluctuations are stronger in the underdoped and overdoped regimes and appear to be weakest at optimal doping.

引用

页数：8