neumann2.py 文件源码

def func_2vN(Ek, Ek_grid, l, eta, hfk):
    """
    Linearly interpolate the value of hfk on Ek_grid at point Ek.

    Parameters
    ----------
    Ek : float
        Energy value (not necessarily a grid point).
    Ek_grid : array
        Energy grid.
    l : int
        Lead label.
    eta : int
        Integer describing (+/-1) if infinitesimal eta is positive or negative.
    hfk : array
        Array containing Hilbert transform of Fermi function (or 1-Fermi).

    Returns
    -------
    float
        Interpolated value of hfk at Ek.
    """
    if Ek<Ek_grid[0] or Ek>Ek_grid[-1]:
        return 0
    #
    b_idx = int((Ek-Ek_grid[0])/(Ek_grid[1]-Ek_grid[0]))+1
    if b_idx == len(Ek_grid): b_idx -= 1
    a_idx = b_idx - 1
    b, a = Ek_grid[b_idx], Ek_grid[a_idx]
    #
    fb = hfk[l, b_idx]
    fa = hfk[l, a_idx]
    rez = (fb-fa)/(b-a)*Ek + (b*fa-a*fb)/(b-a)
    return pi*rez if eta+1 else pi*rez.conjugate()