  In the recent studies of the unconventional physics in cuprate
superconductors, one of the central issues is the interplay between charge
order and superconductivity. Here the mechanism of the charge-order formation
in the electron-doped cuprate superconductors is investigated based on the t-J
model. The experimentally observed momentum dependence of the electron
quasiparticle scattering rate is qualitatively reproduced, where the scattering
rate is highly anisotropic in momentum space, and is intriguingly related to
the charge-order gap. Although the scattering strength appears to be weakest at
the hot spots, the scattering in the antinodal region is stronger than that in
the nodal region, which leads to the original electron Fermi surface is broken
up into the Fermi pockets and their coexistence with the Fermi arcs located
around the nodal region. In particular, this electron Fermi surface instability
drives the charge-order correlation, with the charge-order wave vector that
matches well with the wave vector connecting the hot spots, as the charge-order
correlation in the hole-doped counterparts. However, in a striking contrast to
the hole-doped case, the charge-order wave vector in the electron-doped side
increases in magnitude with the electron doping. The theory also shows the
existence of a quantitative link between the single-electron fermiology and the
collective response of the electron density.
