  We develop a general Ginzburg-Landau theory which describes the effect of a
Zeeman field on the superconducting order parameter in triplet superconductors.
Starting from Ginzburg-Landau theories that describe fully gapped time-reversal
symmetric triplet superconductors, we show that the Zeeman field has dramatic
effects on the topological properties of the superconductors. In particular, in
the vicinity of a critical chemical potential separating two topologically
distinct phases, it is possible to induce a phase transition to a topologically
nontrivial phase which supports chiral edge modes. Moreover, for specific
directions of the Zeeman field, we obtain nodal superconducting phases with an
emerging chiral symmetry, and with Majorana flat bands at the edge. The
Ginzburg-Landau theory is microscopically supported by a self-consistent
mean-field theory of the doped Kitaev-Heisenberg model.
