Influence Of Spin-orbit Interaction Research Articles

Manifestation of spin-orbit interaction in tunneling between two-dimensional electron layers

An influence of spin-orbit interaction on the tunneling between two two-dimensional electron layers is considered. Particular attention is addressed to the relation between the contribution of Rashba and Dresselhaus types. It is shown that without scattering of the electrons, the tunneling conductance can either exhibit resonances at certain voltage values or be substantially suppressed over the whole voltage range. The dependence of the conductance on voltage turns out to be very sensitive to the relation between Rashba and Dresselhaus contributions even in the absence of magnetic field. The elastic scattering broadens the resonances in the first case and restores the conductance to a larger magnitude in the latter one. These effects open the possibility to determine the parameters of spin-orbit interaction and electron scattering time in tunneling experiments with no necessity of external magnetic field.

The spectral fine structure, zero-field splitting parameters and Jahn-Teller effect of LiNbO3∶Fe3+crystals

The 252 rank completely diagonalized Hamiltonian matrix of the 3d5 configuration with trigonal symmetry have been established by group theory, crystal field theory and irreducible tensor operator method. The spectral fine structure, zero-field splitting parameters, and Jahn-Teller effect, as well s the influence of spin doublet state and spin quartet state on the ground-state energy levels in LiNbO3∶Fe3+ crystals were studied with this matrix. The results show that the contribution of spin quartet state on the ground- state energy levels is the most important, the contribution of spin doublet state is weak but can not be neglected. The calculated results are in good agreement with the experiments. On their basis, the influence of spin-orbit interaction and spin-spin interaction on the spectra fine structure and zero-field splitting parameters were further studied, and we found that the influence of spin-orbit interaction is dominant, but the influence of spin-spin interaction can not be neglected. The research shows this substance has J-T effect in the spectral structure of spin quartet state. The reason is the combined action of spin-orbit interaction and trigonal distortion.

Reduction of uranyl by hydrogen: an ab initio study

We present in this paper a systematic investigation of the accuracy of different theoretical approaches to uranyl reduction. All-electron and RECP results are compared at the SCF and different correlated levels, including density functional methods. The comparison is done for geometries and reaction energies. The influence of spin-orbit interaction on energies is also investigated.

Perturbing influence of spin-orbit interaction upon the two-photon absorption in 4fN systems

A complete list of effective operators representing the perturbing influence of spin-orbit interaction upon the single beam two-photon f⟷f absorption between the states of 4fN configurations is presented. The effective operators are expressed in terms of double unit tensor operators, and they are defined within the perturbed function approach. The proposed model is illustrated by the results of numerical calculations performed for the CeM+3 ion.

Picosecond pulsed-field probes of magnetic systems (invited)

Time-resolved methods using picosecond scale transient magnetic fields have been developed for investigations of ultrafast magnetic phenomena in a broad variety of systems. When combined with synchronous magneto-optic detection, the approach yields stroboscopic observations of magnetic dynamics with a time resolution of order 1 ps, and a corresponding spatial resolution down to the diffraction limit of optics. Results are presented from experiments on europium chalcogenide films at low temperatures. A continuum of behavior from paramagnetic relaxation to ferromagnetic resonance is observed. Electron-beam deposited EuS films are found to have surprisingly fast spin-lattice relaxation rates, of order (100 ps)−1, and the influence of spin-orbit interactions on the spin dynamics is studied through rare-earth alloying. Results are presented from experiments utilizing the magneto-optic sampling method for direct time-resolved screening measurements of normal and superconducting metal films.

Experimental characterization of the Xe 5p photoionization by angle- and spin-resolved photoelectron spectroscopy

Spin- and angle-resolved photoelectron spectroscopy with elliptically polarized radiation has been used to fully characterize the dynamics of photoelectron emission from free Xe atoms in the 5p-autoionization and continuum region. An advantageous reaction geometry and its experimental realization at the storage ring BESSY are discussed. The three independent experimental parameters which characterize the angular dependence of the photoelectron spin-polarization vector are reported for the wavelength range from 100nm to 40 nm. The results are compared with theoretical predictions based on RRPA-, RPAE- and semiempirical MQDT-calculations. The combination of existing data for the differential photoionization cross section with the spinpolarization parameters is used to completely decouple the photoionization channels: The transition matrix elements and their relative phases are determined separately for every single dissociation channel. The results are discussed in the context of the MQDT. Correlation effects and the influence of spin-orbit interaction on the continuum states most clearly show up when the Dill-Fano angular-momentum-transfer formalism is applied.

Magnetoresistivity of single-crystal films of iron, cobalt, and nickel binary alloys

Magnetoresistivity measurements of binary systems of alloy films Fe-Co, Fe-Ni, and Co-Ni in the [100] direction for the alloy systems Fe-Co and Fe-Ni up to 25 wt. % Co and Ni, respectively, and in the [100] direction for the remaining alloys are presented. A test of Berger's theory on the influence of spin-orbit interaction on transition processes in ferromagnetic alloys of nickel is carried out. The results obtained are compared with the results derived from bulk polycrystalline samples [1, 2].

Influence of spin-orbit interaction on the transport processes in ferromagnetic nickel alloys, in the presence of a degeneracy of the 3d band

Assuming that two of the five branches of the 3d band intersect, it is shown that singularities result in the transport properties when such an intersection happens to occur at the Fermi level. The “ferromagnetic anisotropy of resistivity” Δϱ/ϱ0 (often called magnetoresistance effect) is expected to have a strong maximum; using Born approximation for impurity scattering, and simple models of the 3d and 4s bands, a detailed computation provides an order of magnitude of 20% for the value of Δϱ/ϱ0 at the maximum. On the other hand, assuming the validity of current theories of the “extraordinary Hall conductivity” γ HS due to Smit or to Karplus and Luttinger, γ HS may be expected to change sign. This is precisely the behaviour of Δϱ/ϱ0 and γ HS observed by Smit in Co-Ni and Fe-Ni alloys, for an electron concentration equal to 27.7 electrons per atom.

Influence of Spin-Orbit Interaction on the Transport Processes in Ferromagnetic Nickel Alloys, in the Presence of a Degeneracy of the 3d Band

Assuming that two of the five branchs of the 3d band intersect, it is shown that singularities result in the transport properties when such an intersection happens to occur at the Fermi level. The ``ferromagnetic anisotropy of resistivity'' Δρ/ρ0 (often called magnetoresistance effect) is expected to have a strong maximum; using Born approximation for impurity scattering, and simple models of the 3d and 4s bands, a detailed computation provides an order of magnitude of 20% for the value of Δρ/ρ0 at the maximum. On the other hand, assuming the validity of current theories of the ``extraordinary Hall conductivity'' γHs due to Smit or to Karplus and Luttinger, γHs may be expected to change sign. This is precisely the behavior of Δρ/ρ0 and γHs observed by Smit in Co-Ni and Fe-Ni alloys, for an electron concentration equal to 27.7 electrons/atom.