标题： 量子阱中自旋分裂的有效单带方法 显示英文标题

标题： Effective one-band approach for the spin splittings in quantum wells

摘要： 二维电子在由III-V半导体生长的量子阱中的自旋-轨道相互作用由两个具有不同对称性的部分组成：Bychkov-Rashba项和Dresselhaus项。最后一项通常归因于体自旋-轨道哈密顿量，它反映了闪锌矿晶格的Td对称性。虽然已知量子阱界面也可能对Dresselhaus项有贡献，但界面和体贡献的精确结构以及相对重要性尚不明确。为了将体贡献与界面贡献进行比较，我们对[100] GaAs/AlGaAs量子阱中电子能级的自旋分裂进行了紧束缚计算，并在包含Dresselhaus项两个界面贡献的一带有效质量电子哈密顿量框架内分析了所得的自旋分裂。我们表明，自旋分裂随量子阱宽度和沿生长方向电场的变化关系可通过解析的一带计算完美再现，而对于足够窄的量子阱，界面贡献的自旋-轨道相互作用的大小与体Dresselhaus哈密顿量的贡献在同一数量级。 显示英文摘要

摘要： The spin-orbit interaction of 2D electrons in the quantum wells grown from the III-V semiconductors consists of the two parts with different symmetry: the Bychkov-Rashba and the Dresselhaus terms. The last term is usually attributed to the bulk spin-orbit Hamiltonian which reflects the Td symmetry of the zincblende lattice. While it is known that the quantum well interfaces may also contribute to the Dresselhaus term, the exact structure and the relative importance of the interface and the bulk contributions are not well understood yet. To compare the bulk contribution with the interface one, we perform tight-binding calculations of the spin splittings of the electron levels in [100] GaAs/AlGaAs quantum wells and analyze the obtained spin splittings within the one-band effective mass electron Hamiltonian containing the two interface contributions to the Dresselhaus term. We show that the dependencies of the spin splittings on the quantum well width and the electric field along the growth direction are perfectly reproduced by the analytical one-band calculations and the magnitude of the interface contribution to the spin-orbit interaction for sufficiently narrow quantum wells is of the same order as the contribution from the bulk Dresselhaus Hamiltonian.