  The recently discovered charge order is a generic feature of cuprate
superconductors, however, its microscopic origin remains debated. Within the
framework of the fermion-spin theory, the nature of charge order in the
pseudogap phase and its evolution with doping are studied by taking into
account the electron self-energy (then the pseudogap) effect. It is shown that
the antinodal region of the electron Fermi surface is suppressed by the
electron self-energy, and then the low-energy electron excitations occupy the
disconnected Fermi arcs located around the nodal region. In particular, the
charge-order state is driven by the Fermi-arc instability, with a
characteristic wave vector corresponding to the hot spots of the Fermi arcs
rather than the antinodal nesting vector. Moreover, although the Fermi arc
increases its length as a function of doping, the charge-order wave vector
reduces almost linearity with the increase of doping. The theory also indicates
that the Fermi arc, charge order, and pseudogap in cuprate superconductors are
intimately related each other, and all of them emanates from the electron
self-energy due to the interaction between electrons by the exchange of spin
excitations.
