Doping dependence of the electron-doped cuprate superconductors from the antiferromagnetic properties of the Hubbard model

Abstract

Within the Kotliar-Ruckenstein slave-boson approach, we have studied the antiferromagnetic (AF) properties for the t-t ′ -t ′′ -U model applied to electron-doped cuprate superconductors. It is found that, due to the inclusion of quantum fluctuations, the AF order decays with increasing doping much faster than obtained in the Hartree-Fock theory. Under an intermediate constant U the calculated doping evolution of the spectral intensity in the AF state has satisfactorily reproduced the experimental results, without need of a strongly doping-dependent U as argued earlier. This may reconcile a discrepancy in recent studies on photoemission and optical conductivity.

Spectral properties near the Mott transition in the two-dimensional Hubbard model with next-nearest-neighbor hopping

“…For the pseudogap around (π/2,π/2) in electron-doped systems, there are several interpretations, such as that it is the result of the band splitting caused by antiferromagnetic long-range order [12][13][14][15][16][17][18][19][20][21][22], short-range antiferromagnetic correlations [23][24][25][26], renormalization of the Fermi surface by interactions [28], or zeros of the Green function [29].…”

“…3(b)-3(e) and 3(g)-3(j)] [6][7][8][9][10][11] can be interpreted as a separation of the modes due to the large shift of the flat mode around (π,0) caused by next-nearest-neighbor hopping. In electron-doped systems near the Mott transition, the mode fading away toward the Mott transition can be effectively separated around ω = 0 from the continuum for ω > 0 around (π/2,π/2) as a [3][4][5][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]32,36]. For details, further investigations, including careful analyses on finite-size effects in CPT, are necessary.…”

X-ray imaging of dispersive charge modes in a doped Mott insulator near the antiferromagnet/superconductor transition

“…While previous studies have focused largely on either undoped one-dimensional 8 or two-dimensional 4,5 insulators, or hole-doped superconductors, 9 Mott insulators can be doped with electrons as well. In fact, it appears that with electron doping, cuprate bands evolve in a much more straightforward and systematic manner [10][11][12][13][14] than with hole doping. A limited previous work 15 that focused on a superconductor with a fit to the one-band theory does not provide insights into the way the collective modes of a nonsuperconducting Mott insulator evolve into a superconductor wherein the high-energy excitations of the Mott insulator are intimately connected to the lower-energy physics of the superconductor.…”

Nonmonotonic gap in the coexisting antiferromagnetic and superconducting states of electron-doped cuprate superconductors

“…16 The similar calculation at optimal doping was previously undertaken, but limited to the pure AF state. 18,19,20 To match the experimental situation at x = 0.15 and low temperature T < T c , 16 the coexisting state including the SC order is necessary. For primitive physical electrons, which are represented by operatorsc kσ [equal to c † kσ in Hamiltonian (1)], the Matsubara Green's function isḠ σ (k,…”