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Abstract: In this paper, we theoretically investigate the conductance and the magnetoresistance effect in a periodically magnetically modulated two-dimensional electron gas. It is shown that there exists a significant conductance difference for electrons through the parallel and antiparallel magnetization configurations, which leads to a considerable magnetoresistance effect. It is also shown that the conductance and the magnetoresistance effect depend on both the temperature and the number of the periodic magnetic barriers. [Copyright &y& Elsevier]

Abstract: In this letter, we study the phonon ballistic transmission and the thermal conductivity in a dielectric quantum waveguide with one or two defect regions. The results show that these observable quantities strikingly depend on geometric parameters, and are of quantum character. The total transmission coefficient versus the reduced waveguide-length exhibits periodical behavior. Our results also show that one can control the thermal conductivity of the structure and make different acoustic filters by adjusting the geometric parameters. [Copyright &y& Elsevier]

Abstract: In this paper, we theoretically investigate the effect of the bias and temperature on the electron transport properties in a magnetic nanostructure. It is found that the large spin-polarization can be achieved in such a nanostructure, and the degree of spin-polarization obviously increases with increasing applied bias. It is also found that the conductance curves for the different temperatures obviously intersect at the same Fermi energy for the low Fermi energy, and the degree of spin-polarization decreases with the increase of temperature. Thus, we can control the electron transport through changing the bias and temperature. [Copyright &y& Elsevier]

Abstract: Using the transfer matrix method, the transmission probability, the spin polarization and the electron conductance of a ballistic electron are studied in detail in a nanostructure. We observe that these quantities sensitively depend on the number of periodic magnetic–electric barriers. As the number of periods increases, the resonance splitting increases, the number of the resonance peaks increases and the peaks become sharper as well as the spin polarization being enhanced. Surprisingly, a polarization of nearly 100% can be achieved by spin-dependent resonant tunneling in this structure, although the average magnetic field of the structure is zero. [Copyright &y& Elsevier]

Abstract: The electron transport properties are theoretically investigated in a nanostructure under the influence of magnetic barriers and the δ-doping. The resulting transmission and spin polarization are strongly dependent on the weight of δ-doping. It is shown that the large spin polarization can be achieved due to the remarkable discrepancy in the transmission for electrons with opposite spin orientations. It is also shown that both the transmission probability and the spin polarization periodically change with the increase of L. These interesting features will be more helpful for developing new types of spintronic devices. [Copyright &y& Elsevier]

Abstract: Using the transfer matrix method, the transmission probability, the spin polarization and the conductance of the ballistic electron are studied in detail in a nanostructure with the periodic applied bias and magnetic barriers. We find that these observable quantities sensitively depend on the number of the periodic magnetic–electric barriers. With the number of the periods increasing, the resonance peaks shift towards right and the number of the resonance peaks is increasing as well as the spin polarization being enhanced. These interesting properties may be helpful for making the bias-tunable spin filter. [Copyright &y& Elsevier]