Energy dependent spin filtering by using Fano effect in open quantum rings

An open quantum ring containing magnetic quantum structures which is subjected to the Rashba spin-orbit coupling and Zeeman effect is considered. One dimensional quantum wave guide theory is developed and Transfer matrix method in conjunction with spin-dependent Griffith's boundary condition is used to calculate the transmission coefficients of the corresponding one-electron scattering problem. Investigations into spin-dependent transport show the characteristic oscillations which are affected by impurities. The existence of Rashba spin-orbit coupling leads to the appearance of Fano resonances in transport. The results indicate that the orientation of Fano line shapes is under the influence of impurities. Also, it is shown that by using Fano resonances the system under study can be used as a cent percent spin-filtering device. The spin-filtering property of this system as a function of energy is affected by impurities and can be used in order to design optimized nanodevices. (C) 2010 Elsevier Ltd. All rights reserved.