Strong nodeless pairing on separate electron Fermi surface sheets in (Tl, K)Fe${}_{1.78}$Se${}_2$ probed by ARPES

X. -P. Wang, T. Qian, P. Richard +6

We performed a high-resolution angle-resolved photoemission spectroscopy study of the Tl${}_{0.63}$K${}_{0.37}$Fe${}_{1.78}$Se${}_2$ superconductor ($T_c=29$ K). We show the existence of t…