  We perform a numerical study on the spin-resolved transport in a quantum wire
(QW) under the modulation of both Rashba spin-orbit coupling (SOC) and a
perpendicular magnetic field (MF) by adopting the developed Usuki
transfer-matrix method in combination with the Landauer-Buttiker formalism.
Wide spin filtering energy windows can be achieved in this system for a
spin-unpolarized injection. In addition, both the width of these energy windows
and the magnitude of the spin conductance within these energy widows can be
tuned by varying the Rashba SOC strength, which can be apprehended by analyzing
the energy dispersions and the spin-polarized density distributions inside the
QW, respectively. Further study also demonstrates that these
Rashba-SOC-controlled spin filtering energy windows show a strong robustness
against disorders. These findings may not only benefit to further understand
the spin-dependent transport properties of the QW in the presence of external
fields but also provide a theoretical instruction to design a spin filter
device.
