Radius effect on the spintronic properties of a triangular network of quantum nanorings in the presence of Rashba spin-orbit interaction

The effect of radius on conductance and spin transport through a triangular array of quantum nanorings (QR) in the presence of Rashba spin-orbit interaction (RSOI) is studied. By using wave-guide theory, we obtain the conductance through such network as a function of RSOI strength and the wave vector k of the incoming electrons, with rings of equal and different radius. It is shown that in the network with rings of different radius and local modulations of RSOI, the input current can be directed to any of output ports, so it can be used as a switching device. In addition, in the certain ranges of k, the network can be perfectly opaque, depending on the value of RSOI strength and ring radius. Besides, considerable pure spin currents can be revealed in the two output leads with the same amplitude and reverse polarizations.