docs: def plot_dop_phase(bands, int_max, hund_cu):
      """Phase plot of Quasiparticle weight for N degenerate bands
         under doping shows transition only at interger filling
         the rest are metallic states"""
      name = 'Z_dop_phase_'+str(bands)+'bands_U'+str(int_max)+'J'+str(hund_cu)
      dop = np.sort(np.hstack((np.linspace(0.01,0.99,50),
                      np.arange(1./2./bands, 1, 1/2/bands))))
      data = ssplt.calc_z(bands, dop, np.arange(0, int_max, 0.1), hund_cu, name)
  
      ssplt.imshow_z(data, name)
      ssplt.surf_z(data, name)