  We investigate the time evolution of the six-component electron pressure
tensor in a hybrid code studying consequences for the two-dimensional
reconnection process in an initially perturbed Harris sheet. We put forward
that two tensor components (a diagonal and a non-diagonal one) grow in an
unstable way unless an isotropization operator is considered. This
isotropization term is physically associated with an electron heat flux. As a
consequence, we put forward that an enhanced value of a diagonal component is
observed in the very middle of field reversal at sub-ion scale. Because of the
increase of the kinetic pressure, the magnetic field is decreased in this
electron layer, hence increasing the associated out-of-plane current at its
edges and leading to its bifurcation. The bifurcation mechanism is based on the
presence of electron pressure anisotropy, related to the gradient of inflow
electron bulk velocity. The gradient in the inflow direction of the enhanced
diagonal electron pressure tensor component results in the deceleration of the
ions entering the X-point region. We suggest that bifurcated current sheets
resulting from the anisotropies/agyrotropies of the six-component electron
pressure tensor correspond to smaller reconnection rates comparing to
non-bifurcated ones.
