Magnetic Penetration Depth in the FeAs-Based Superconductor KFe₂As₂

Abstract

Transverse-field muon spin rotation measurements were performed on the iron-based superconductor, KFe 2 As 2 , in order to investigate the superconducting gap mechanism. We found that the temperature dependence of the magnetic penetration depth λ shows multiple gap-like behavior and that λ depends on the field. These results suggest the existence of quasiparticle excitations outside the vortices.

A brief review on μSR studies of unconventional Fe- and Cr-based superconductors

“…The temperature and field dependence of TF-µSR measurements yields information about the flux-line lattice and magnetic penetration depth, which can reveal the structure of the superconducting gap. Furthermore, TF-µSR measurements on single crystals can allow for the gap anisotropy to be directly probed 101,102 . µSR in zero-field can be used to determine whether time reversal symmetry is broken in the superconducting state, as well as the magnetic properties of the system.…”

Dependence of the absolute value of the penetration depth in (Ba1−xKx)Fe2As2Almoalem1, Yagil2, Cho3 et al. 2018Phys. Rev. B130120View full textAdd to dashboardCite

“…In addition, it is thought that Ba 1−x K x Fe 2 As 2 is less disordered than other pnictides because the Ba sites hosting the K dopants are off the Fe-As planes 16,17,25,26 . All of this has motivated much research on superconductivity in Ba 1−x K x Fe 2 As 2 [16][17][18][27][28][29] , as well as on the structural 3,30 and electronic 17,31 properties.…”