  Majorana fermions are predicted to arise at the ends of nanowire devices
which combine superconductivity, strong spin-orbit coupling and an external
magnetic field. By manipulating networks of these devices with suitable gating,
it has been suggested that braiding operations may be performed which act as
logic operations, suitable for quantum computation. However, the unavoidable
misalignment of the magnetic field in any realistic device geometry has raised
questions about the feasibility of such braiding. In this paper, we numerically
simulate braiding operations in devices with Y-junction and tuning fork
geometries using an experimentally motivated nanowire model. We study how the
static and dynamical features vary with geometric parameters and identify
parameter choices that optimise the probability of a successful braid. Notably,
we find that there is an optimal Y-junction half-angle (about 20 degrees for
our parameter values), which balances two competing mechanisms that reduce the
energy gap to excitations. In addition, we find that a tuning fork geometry has
significant advantages over a Y-junction geometry, as it substantially reduces
the effect of dynamical phase oscillations that complicate the braiding
process. Our results suggest that performing a successful braid is in principle
possible with such devices, and lies within experimental reach.
