Spin Hall effect in a square 2DEG sample with a central defect

We study spin and charge accumulation and currents in two-dimensional electron gas (2DEG) with spin-orbit Rashba interactions. The Landauer-Keldysh formalism is employed to numerically compute the accumulations and currents in a 2DEG finite square sample with and without an embedded spin-independent hard-wall impurity. We find that under certain conditions the charge accumulation and the spin currents may be confined to a small region of the sample, between the defect and the positive lead. The conditions for the existence of this phenomenon are described.