Numerical Study of Spin-Dependent Transport Through a Magnetic Quantum Wire with Lattice Vacancy

The impact of lattice vacancy on the spin dependent transport properties of a magnetic-quantum wire (MQW) has been investigated. A simple tight binding Hamiltonian to describe the model is used, where the quantum wire is attached to two semi-infinite one-dimensional non-magnetic electrodes. Based on the Landauer-Buttiker formalism all the calculations are performed numerically which describe two-terminal conductance. The results suggest that in presence of vacancy the transmission reduces and vacancy creates quasilocalized states around zero energy (E-f = 0). In order to investigate spin-filtering effect of (MQW), the degree of polarization in the presence and absences of vacancy has been studied. Also it is found that the effect of vacancy decreases when the size of MQW increases. The results show that a magnetic quantum wire can be used as a spin filter. The application of the predicted results may be useful in designing molecular spin-polarized transistors in the future.