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Transport and thermoelectric coefficients (including also spin thermopower) of silicene nanoribbons with zigzag edges are investigated by ab-initio numerical methods. Local spin density of such nanoribbons reveals edge magnetism. Like in graphene, one finds antiferromagnetic and ferromagnetic ordering, with spin polarization at one edge antiparallel or parallel to that at the other edge, respectively. Thermoelectric properties, especially the Seebeck coefficient, significantly depend on the electronic band structure and are enhanced when the Fermi level is in the energy gap. However, these thermoelectric properties are significantly reduced when the phonon contribution to the heat conductance is included. This phonon contribution has been calculated numerically by two different methods. Transition from antiferromagnetic to ferromagnetic states leads to a large magnetoresistance as well as to a considerable magnetothermopower. Thermoelectric parameters in the antiparallel configuration, when spin polarization in the left part of the nanoribbon is opposite to that in the right part, are also analyzed.

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Nonequilibrium Green's function technique has been used to calculate spin-dependent electronic transport through a quantum dot in the Kondo regime. The dot is described by the Anderson Hamiltonian and is coupled either symmetrically or asymmetrically to ferromagnetic leads, whose magnetic moments are noncollinear. In symmetrical systems the splitting of the Kondo anomaly in differential conductance decreases monotonically with an increasing angle between magnetizations and vanishes in the antiparallel configuration. The corresponding behavior in asymmetrical systems may be different, i.e., the splitting of the anomaly can vary nonmonotonically with the angle between magnetizations and can remain finite in the antiparallel configurations. A significant asymmetry with respect to bias reversal has also been found in asymmetrical systems.

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