Fermi surface evolution and collapse of the Mott pseudogap in ${\mathrm{Nd}}_{2-x}{\mathrm{Ce}}_x{\mathrm{CuO}}_{4\pm \delta }$

Fermi surface (FS) maps and spectral intensities obtained recently in ${\mathrm{Nd}}_{2-x}{\mathrm{Ce}}_x{\mathrm{CuO}}_{4\pm \delta }$ via high resolution ARPES measurements are analyzed using mean-field Hartree Fock and self-consistent renormalization computations within the framework of the one-band $t-t^{\prime }-t^{″}-U$ Hubbard model Hamiltonian. We show that the remarkable observed crossover of the FS from small to large sheets reflects a reduction in the value of the effective Hubbard U with increasing electron doping and the collapse of the correlation induced Mott pseudogap just above optimal doping.