  We study spontaneous symmetry breaking in phi^4_(1+1) using the light-front
formulation of the field theory. Since the physical vacuum is always the same
as the perturbative vacuum in light-front field theory the fields must develop
a vacuum expectation value through the zero-mode components of the field. We
solve the nonlinear operator equation for the zero-mode in the one-mode
approximation. We find that spontaneous symmetry breaking occurs at
lambda_critical = 4 pi(3+sqrt 3), which is consistent with the value
lambda_critical = 54.27 obtained in the equal time theory. We calculate the
value of the vacuum expectation value as a function of the coupling constant in
the broken phase both numerically and analytically using the delta expansion.
We find two equivalent broken phases. Finally we show that the energy levels of
the system have the expected behavior within the broken phase.
