[en] The substrate contribution to the magnetic anisotropy energy (MAE) of supported nanostructures can be assessed by a site-selective manipulation of the spin–orbit coupling (SOC) and of the effective exchange field B_ex. A systematic study of Co adatoms and Co monolayers on the (1 1 1) surfaces of Cu, Ag, Au, Pd and Pt is performed to study common trends in this class of materials. It is found that for adatoms, the influence of the substrate SOC and B_ex is relatively small (10–30% of the MAE) while for monolayers, this influence can be substantial. The influence of the substrate SOC is much more important than the influence of the substrate B_ex, except for highly polarizable substrates with a strong SOC (such as Pt). The substrate always promotes the tendency to an out-of-plane orientation of the easy magnetic axis for all the investigated systems. (paper)

[en] We have extended the considerable computational advantages of separable, nonlocal pseudopotentials to the calculation of spin-orbit splittings in solids. We write the total ionic pseudopotential as a sum of scalar relativistic and spin-orbit contributions, where each term can be represented by a fully nonlocal potential of the separable Kleinman-Bylander (KB) form. The scalar term, which reduces to the standard KB expression for the pseudopotential in the limit where one can neglect spin-orbit interactions, is used in the local-density approximation to calculate zeroth-order electronic properties in the usual way, and spin-orbit splittings are calculated to first order using perturbation theory. We have tested our procedure by calculating the spin-orbit splittings at high symmetry points of the zinc-blende III-V semiconductors GaAs, InAs, AlSb, GaSb, and InSb. The calculated splittings in all cases are in excellent agreement with those obtained from other first-principles calculations and with experiment. Since our spin-orbit operator is fully nonlocal in both radial and angular coordinates, a considerable reduction in the labor required to calculate matrix elements has been achieved. This makes our approach ideally suited for use with ab initio molecular-dynamics techniques, which currently have become the methods of choice for exploring the electronic and structural properties of solids

No abstract available

[en] A general spinor interaction with gravitation which includes both Einstein's and Cartan's theories as special cases is discussed. The coupling of torsion to matter field in the new theory has an arbitrary strength which can only be determined by experiment. (author)

[en] We have been developing computational methods to calculate electronic structures of molecules using relativistic effective core potentials with spin-orbit terms. Since spin-orbit interactions are contained in the Hamiltonian employed to derive one electron wavefunctions, orbitals in the present method become two-component spinors confirmining the double group symmetry. Starting from the HF method using two-component molecular spinors, the present scheme has been extended to relativistic MP2 and CI methods. These two-component methods are especially useful to study the interplay between spin-orbit and correlation effects on molecular structures and properties. Results calculated by the present methods are available for many diatomic molecules and a few polyatomic systems

[en] We investigate the localization-delocalization transition of a two-dimensional system with spin-orbit interaction (SOI) in a perpendicular magnetic field. We find that if the system is set between two Landau levels, the increase of SOI strength g can drive the system first from localization state into delocalization state, then back to localization state. Scaling analysis shows that near the transition points the behavior of the correlation length ξ can be well described by function ξ=Aexp(α vertical bar g_c-g vertical bar), with vertical bar g_c-g vertical bar being the distance from the transition point, A being a constant and α being exponent, suggests that Kosterlitz-Thouless nature of the transitions, different from the continuous transition in the absence of the magnetic field

[en] We theoretically investigate spin transport in the elliptical ring and the circular ring with Rashba spin–orbit interaction. It is shown that when Rashba spin–orbit interaction is relatively weak, a single circular ring can not realize spin flip, however an elliptical ring may work as a spin-inverter at this time, and the influence of the defect of the geometry is not obvious. Howerver if a giant Rashba spin–orbit interaction strength has been obtained, a circular ring can work as a spin-inverter with a high stability. (paper)

[en] The spin-resolved electron transport through a triangular network of quantum nanorings is studied in the presence of Rashba spin-orbit interaction (RSOI) and a magnetic flux using quantum waveguide theory. This study illustrates that, by tuning Rashba constant, magnetic flux and incoming electron energy, the triangular network of quantum rings can act as a perfect logical spin-filtering with high efficiency. By changing in the energy of incoming electron, at a proper value of the Rashba constant and magnetic flux, a reverse in the direction of spin can take place in the triangular network of quantum nanorings. Furthermore, the triangular network of quantum nanorings can be designed as a device and shows several simultaneous spintronic properties such as spin-splitter and spin-inverter. This spin-splitting is dependent on the energy of the incoming electron. Additionally, different polarizations can be achieved in the two outgoing leads from an originally incoming spin state that simulates a Stern-Gerlach apparatus.

[en] An explicit analytic expression is derived for the magnetic moment of a 2D electron gas taking into account the spin-orbit interaction in the Rashba model with T = 0. The cases of constant chemical potential and number of electrons are investigated. The magnetic field and temperature dependences of the magnetic moment are analyzed. The results are compared with the results of experimental studies of magnetization

[en] We use rotational gravity darkening in the disk of Kepler star KOI-2138 to show that the orbit of $2.1-<!--\; ???\; -->R_{\oplus <!--\; ???\; -->}$ transiting planet candidate KOI-2138.01 has a low projected spin–orbit alignment of $\mathrm{\lambda <!--\; ??\; -->}=1^{\circ <!--\; ???\; -->}\pm <!--\; ??\; -->{13}^{\circ <!--\; ???\; -->}$. KOI-2138.01 is just the second super-Earth with a measured spin–orbit alignment after 55 Cancri e, and the first to be aligned. With a 23.55 days orbital period, KOI-2138.01 may represent the tip of a future iceberg of solar-system-like terrestrial planets having intermediate periods and low-inclination circular orbits.