  Established techniques for deterministically creating dark solitons in
repulsively interacting atomic Bose-Einstein condensates (BECs) can only access
a narrow range of soliton velocities. Because velocity affects the stability of
individual solitons and the properties of soliton-soliton interactions, this
technical limitation has hindered experimental progress. Here we create dark
solitons in highly anisotropic cigar-shaped BECs with arbitrary position and
velocity by simultaneously engineering the amplitude and phase of the
condensate wavefunction, improving upon previous techniques which only
explicitly manipulated the condensate phase. The single dark soliton solution
present in true 1D systems corresponds to the kink soliton in anisotropic 3D
systems and is joined by a host of additional dark solitons including vortex
ring and solitonic vortex solutions. We readily create dark solitons with
speeds from zero to half the sound speed. The observed soliton oscillation
frequency suggests that we imprinted solitonic vortices, which for our
cigar-shaped system are the only stable solitons expected for these velocities.
Our numerical simulations of 1D BECs show this technique to be equally
effective for creating kink solitons when they are stable. We demonstrate the
utility of this technique by deterministically colliding dark solitons with
domain walls in two-component spinor BECs.
