Theoretical Study On Spin Transport Properties Of Low Dimensional Thin Films

Microelectronics has penetrated into millions of households and is closely related to the life of everyone.Almost everyone cannot leave mobile phones,computers,televisions and other electronic products.With decades of research and development,today's microelectronics technology also is faced with many problems.With the development of Quantum anomalous Hall Effect and Quantum spin Hall Effect,low-dimensional materials have also attracted more and more attention of researchers.The realization of more efficient spin transport in low-dimensional materials represents the realization of smaller electronic devices,more efficient energy transfer,and faster information transfer.Therefore,spin transport in low-dimensional materials is one of the research hotspots in recent years.In this paper,theoretical derivation and first-principles calculations are used to analyze the typical low-dimensional thin film structures of organic semiconductor thin-film devices and the weyl semimetal-TaAs,respectively.The electrons spin transport of the organic semiconductor thin-film device and the conductivity and the seebeck coefficient of TaAs are given by formula and results.The main research contents of this article are:(1)A new double-T ferromagnetic/organic semiconductor/ferromagnetic structure model has been established,and the spin injection conditions in the double-T ferromagnetic/organic semiconductor/ferromagnetic structural model has been deduced through the derivation of theoretical formulae.(2)Incorporating the specific values into the derived formula to study the changes of the spin-polarized currents when spin injected in the double-T ferromagnetic/organic semiconductor/ferromagnetic structure model.The relationship between the spin transport and each variable.(3)Perform the first-principles calculations on the TaAs model constructed,and study the conductivity of the TaAs in the case of obtaining the Dirac point in the energy band.Not only the specific values of TaAs are given,but also the conductivity of the material in each direction component of the density matrix under different conditions for each variable curve are given.(4)we also have studied the Seebeck coefficient of the TaAs material and further deepened our understanding of TaAs by giving specific values and changing curves for each variable,to lay a theoretical foundation for experimental research.