We study the ground state of the Gross Pitaveskii energy in a strip, with a
phase imprinting condition, motivated by recent experiments on matter waves
solitons. We prove that when the width of the strip is small, the ground state
is a one dimensional soliton. On the other hand, when the width is large, the
ground state is a solitonic vortex. We provide an explicit expression for the
limiting phase of the solitonic vortex as the size of the strip is large: it
has the same behaviour as the soliton in the infinite direction and decays
exponentially due to the geometry of the strip, instead of algebraically as
vortices in the whole space