Extended Data Fig. 4: Determination of the tight-binding parameters.
From: Unconventional spectral signature of Tc in a pure d-wave superconductor
a, The dispersion of the antibonding band near the chemical potential (coloured circles) is extracted from ARPES data taken at 250 K on an overdoped Bi2212 sample with a slightly different doping (p ≈ 0.196 from ref. 8). The temperature is chosen such that there are no gaps and more dispersion above the chemical potential can be identified. Data from different momentum cuts (as marked in b) are offset in steps of 0.1 eV for clarity. All data points are fitted at once to the tight-binding expression and the results are plotted as grey crosses. b, Momentum locations of data in a (coloured dots) plotted together with the antibonding Fermi surface (black curves) calculated from the fitting results. The black lines mark the first Brillouin zone. c. As in Fig. 2a, with the tight-binding dispersion plotted in grey. To compensate for the doping difference, we fix t0, t1, and reduce μ by 2.5 meV such that the Van Hove energy from the tight-binding model matches that of the OD77 (p ≈ 0.210) sample studied in the text.
