Weak Superconducting Pairing and a Single Isotropic Energy Gap in Stoichiometric LiFeAs

Weak superconducting pairing and a single isotropic energy gap in stoichiometric LiFeAs.

We report superconducting (SC) properties of stoichiometric LiFeAs (T(c)=17 K) studied by small-angle neutron scattering (SANS) and angle-resolved photoemission (ARPES). Although the vortex lattice exhibits no long-range order, well-defined SANS rocking curves indicate better ordering than in chemically doped 122 compounds. The London penetration depth lambda(ab)(0)=210+/-20 nm, determined from...

Subharmonic energy-gap structure in superconducting weak links.

Probing the order parameter of superconducting LiFeAs using Pb/LiFeAs and Au/LiFeAs point-contact spectroscopy

Xiaohang Zhang,1,* Bumsung Lee,2 Seunghyun Khim,2 Kee Hoon Kim,2 Richard L. Greene,1 and Ichiro Takeuchi3 1CNAM and Department of Physics, University of Maryland, College Park, Maryland 20742, USA 2CeNSCMR, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, South Korea 3Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20...

Two distinct superconducting phases in LiFeAs

A non-trivial temperature evolution of superconductivity including a temperature-induced phase transition between two superconducting phases or even a time-reversal symmetry breaking order parameter is in principle expected in multiband superconductors such as iron-pnictides. Here we present scanning tunnelling spectroscopy data of LiFeAs which reveal two distinct superconducting phases: at = 1...

Heavily electron - doped electronic structure and isotropic superconducting gap

Y. Zhang, L. X. Yang, M. Xu, Z. R. Ye, F. Chen, C. He, J. Jiang, B. P. Xie, J. J. Ying, X. F. Wang, X. H. Chen, J. P. Hu, and D. L. Feng ∗ State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (MOE), and Department of Physics, Fudan University, Shanghai 200433, People’s Republic of China Hefei National Laboratory for Physical Sciences at Microscale and De...