  In this work, we investigate the characteristics of the electric current in
the so-called symmetric Anderson impurity model. We study the nonequilibrium
model using two complementary approximate methods, the perturbative quantum
master equation approach to the reduced density matrix, and a self-consistent
equation of motion approach to the nonequilibrium Green's function. We find
that at a particular symmetry point, an interacting Anderson impurity model
recovers the same steady-state current as an equivalent non-interacting model,
akin a two-band resonant level model. We show this in the Coulomb blockade
regime for both high and low temperatures, where either the approximate master
equation approach and the Green's function method provide accurate results for
the current. We conclude that the steady-state current in the symmetric
Anderson model at this regime does not encode characteristics of a many-body
interacting system.
