  In the framework of Bogoliubov-de Gennes equation, we theoretically study the
Andreev reflection in normal-superconducting junctions based on semi-Dirac
materials. Owing to the intrinsic anisotropy of semi-Dirac materials, the
configuration of Andreev reflection and differential conductance are strongly
orientation-dependent. For the transport along the linear dispersion direction,
the differential conductance exhibits a clear crossover from retro Andreev
reflection to specular Andreev reflection with an increasing bias-voltage, and
the differential conductance oscillates without a decaying profile when the
interfacial barrier strength increases. However, for the transport along the
quadratic dispersion direction, the boundary between the retro Andreev
reflection and specular Andreev reflection is ambiguous, and the differential
conductance decays with increasing the momentum mismatch or the interfacial
barrier strength. We illustrate the pseudo-spin textures to reveal the
underling physics behind the anisotropic coherent transport properties. These
results enrich the understanding of the superconducting coherent transport in
semi-Dirac materials.
