Spin Polarized Transport Of Two-dimensional Electron Gas Through Magnetic Quantum Structure

Electrons have two properties which are charge and spin, the property of charge have a world of application in semiconductor material, and the electron technology,the computer technology and the communication technology developing at very fast speed. the property of spin have a extensive foreground, which became to the focus of condensed matter physics research and attracted more and more attention. The properties of electron spin polarization transport through magnetic quantum structure which have potential application and theoretically research signification was investigated for open out the phenomenal and the rule of electron spin polarization transport through magnetic quantum structure and offer physics model and theory sustain for design spin electron devices which base on these quantum structure. we made system and embedded theoretics research and gained some significative result.By using the scattering matrix method, the properties of two-dimensional electron gas spin polarized transport through step-magnetic barriers structure at different bias voltage are investigated. The results show that the degree of spin polarization (i) is oscillation reduce if the incidence energy increase at zero bias voltage and (ii) reduce slower and the maximum of spin polarization decreases when the number of steps increase in this structure and (iii) enhance significantly in wider energy region at applied bias voltage, and more distinct spin-filtering properties are shown in the step-magnetic barriers.By using the scattering matrix method and theδfunction approach, the properties of two-dimensional electron gas spin polarized transport through anti-symmetrical magnetic superlattices at different bias voltage are investigated. The result show that: (i) the resonant splitting effect of the electronic transmission coefficients are shown with the incident energy increases and the magnetic barriers increases. (ii) splitting effect also shown in the degree of polarization because the degree of transmission coefficients splitting for spin up and spin down electrons are un-synchronous. (iii) the electronic transmission coefficients and the degree of polarization enhance significantly in wider energy region at applied bias voltage, and more distinct spin filtering properties are shown in the anti-symmetrical magnetic superlattices. Universality of resonant splitting of transmission coefficients and the degree of polarization in magnetic superlattices are shown.