Transport and magnetic properties of low dimensional/nanoscale systems
One of our research interest is on the study of transport characteristics of nanoscale systems. We are especially interested in the influence of correlations on the transport characteristics of these systems. In order to study the transport characteristics of these systems, we use the non-equilibrium Green’s function methods.
This method takes into account the electronic structure, correlation effects, band occupations and temperature in the calculation of the current and hence it provides a systematic way to understand the influence of these parameters on the current. We have used this technique to study the tunnel magnetoresistance (TMR) of magnetic tunnel junctions and we find a strong influence of the band occupation of the metallic electrodes on the TMR. The magnetic correlations present in the electrodes are found to suppress the TMR heavily. The TMR of a model tunnel junction obtained from our studies is shown in the following figure.
Magnetic properties of low dimensional/nanoscale systems.
Another area of our interest is the study of the magnetic properties of low dimensional/nanoscale systems. We use the spin-polarized electronic structure calculations, the many body models, the RKKY and the modified RKKY methods to study the magnetic properties of these systems. The temperature dependence of the spin polarization of f-electron systems such as GdS and Eu doped GdS are studied using the s-f model. The interlayer exchange coupling (IEC) between two magnetic layers separated by a non-magnetic spacer layer is studied using the modified RKKY method. We find from our studies that the IEC is found to exhibit oscillatory behavior and it is found to be altered by the band occupation of the magnetic layers. The IEC of a model system obtained from our studies is shown in the following figure.
