Fig. 1: The form of interaction and the parameters extracted from ARPES.
From: Surface coupling in Bi2Se3 ultrathin films by screened Coulomb interaction
a Feynman diagram of the self-energy used in the Dyson equation. The wavy lines and arrows represent boson lines and fermion lines, respectively. The polarization function of Dirac fermions is made of the fermion lines on the opposite surface. b ARPES spectra of 27 QL Bi2Se3 sample. The black dots in b are the peak positions of the surfaces state fitted by MDCs with the Lorentzian function, and the red dotted line is the linear fitting results of two sets of black dots. \({E}_{{{{{{\rm{B}}}}}}}\) is the binding energy and \({k}_{{||}}\) is the in-plane wave vector.
