2012/03/07 by Dong-Jin Jang, Jang, Dong-Jin, J. B. Hong +13
Physics and Astronomy · #FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1203.1362
4 pages, 4 figures
arxiv created 2012/03/07 · arxiv updated 2012/03/08
We report specific heat capacity measurements on a LiFeAs single crystal at temperatures down to 400 mK and magnetic fields up to 9 Tesla. A small specific heat jump at Tc and finite residual density of states at T=0 K in the superconducting (SC) state indicate that there are strong unitary scatterers that lead to states within the SC gap. A sub-linear magnetic field dependence of the Sommerfeld coefficient γ(H) at T=0 K is equally well fitted by both a nodal d-wave gap as well as a sign changing multiband ± s-wave gap. When impurity effects are taken into account, however, the linear temperature dependence of the electronic specific heat Cel/T at low temperatures argues against a nodal d-wave superconducting gap. We conclude that the SC state of LiFeAs is most compatible with the multiband ± s-wave SC state with the gap values Δsmall=0.46 Δlarge.