Search

The energy spectra of Hamiltonian of a single electron confined in a parabolic quantum dot (QD) have been investigated, taking into considerations different external effects such as the Rashba spin–orbit interaction term, applied uniform magnetic field and topological defect. The results show that the topological defect enhances the energy levels, while the increment in the strength of Rashba parameter removes the spin degeneracy and reduces the energy levels. The obtained QD energy spectra are used to study the statistical mean energy from which we consider the behaviour of the magnetization and magnetic susceptibility on the QD. It is found that the topological defects and Rashba terms play important roles in flipping the sign of the magnetic susceptibility from negative (χ < 0) to positive sign (χ > 0). The present results are in very good qualitative agreement compared with the reported ones. [ABSTRACT FROM AUTHOR]

• A high-throughput method for screening bulk spin-split materials were proposed, which inspires an efficient strategy for a rapidly screening of materials with only simple electronic characteristics. • 440 Rashba, 411 Dresselhaus, and 469 Zeeman-type bulk spin-split materials were searched out. • Those materials with strong spin-split energy are promising candidates for energy efficient spintronic devices. Current-induced spin polarization or electric-field-controlled energy splitting shows great potential in the application of spintronic devices, such as spin–orbit torque devices, spin transistors, and so on. These mechanisms are often found in spin-split materials with strong spin-orbital coupling (SOC), which jointly trigger the Rashba, Dresselhaus, or Zeeman effect. The essential criterion to evaluate the strength of SOC is the spin-split energy. Thus, searching for bulk materials with large spin-split energy has attracted great interest. In this work, a high-throughput workflow was designed with the proposed three-point-spin-texture method, and 440 Rashba, 411 Dresselhaus, and 469 Zeeman-type candidate materials with large spin-split energy were screened out. Moreover, the spin-split energy of Rashba material KSnSb, Dresselhaus material TaSi 2 , and Zeeman-type material PtN 2 achieve 0.19 eV, 0.82 eV, and 0.55 eV, respectively. This work significantly expands the materials database for spintronic devices and paves the way for further experimental research. [ABSTRACT FROM AUTHOR]

•.The non-uniform Rashba parameters is observed. •.The size effect of the spatial pattern of the Rashba parameters is studied. • The stability of the Rashba effect as a function of temperature is analyzed. The spatial fluctuation of the Rashba parameter has been a major issue in the development of state-of-the-art spintronic nanodevices. Since stable spin-precession is of vital importance in the spin field-effect transistor (spin-FET), we have developed a Monte Carlo model to justify that the local E-field of heavy dopants is the origin of the fluctuating Rashba parameter. To maintain a stable drain current in spin-FETs, we study how the size of lattice, doping condition, E-field screening, exchange interaction and temperature influence the Rashba interaction in nanomaterials. Our Monte Carlo model can predict the Rashba effect of Graphene/Nickel(1 1 1) substrate at room temperature and presents a path to enhance the Rashba interactions via proximity coupling. More importantly, we have discovered a dip-like structure in the Rashba parameter that strongly scatters the spin states, and we have figured out how to suppress spin fluctuations in the semiconductor channel. Our results are important for the development of the next generation of spin transistors. [ABSTRACT FROM AUTHOR]

Abstract: We report an unambiguous detection of the crytalline anisotropy of the spin-orbit interaction in (001) InAlAs/InGaAs/InAlAs quantum wells using nanofabricated rectangular loop arrays, where the sides of the constituent loops are aligned along either the [110] or [] crystallographic axis. The fabrication and measurements were performed on the epi-wafer samples whose spin properties were characterized previously [Koga et al. Phys. Rev. Lett 89 (2002) 046801]. We find that the experimentally observed spin interference patterns — the amplitude modulation of the Al’tshuler–Aronov–Spivak oscillations as a function of the gate voltage — are in good agreement with the results of the spin interferometer model extended for rectangular loops and including both the Rashba and Dresselhaus spin-orbit interactions. [Copyright &y& Elsevier]

Abstract: We point out that the electric field formed in the surface inversion layer in InAs nanowires leads to effective magnetic fields, due to the Rashba effect, that are mostly aligned along the wire axis, i.e., parallel to the external magnetic field . While this situation leads to some similarities in spin splitting between the Zeeman and Rashba effects, extensive theoretical simulations revealed that large and small spin splittings should take place alternately at Fermi energies with increasing magnetic field , as a result of the competition between the Rashba and Zeeman spin splittings. We suggest that an experimental detection of such characteristics should bring up quantitative insights into the relative strengths between the Rashba and Zeeman magnetic fields. [Copyright &y& Elsevier]

• We examined the role of morphology of intercalation metal layers on Rashba spin–orbit parameter at Dirac Point (DP) of graphene. • Ag and Au metal layers have been considered with different morphologies on SiC substrate. • Results approved that any changes on morphology of metal layers had significant impact on both band splitting and band gap at DP. • Results showed the size of band gap and band splitting were related to the size of hybridization between pz orbitals of graphene and d-orbitals of Au and Ag. • Spin-texture of SiC/metal/Graphene revealed how spin direction of electron pined to x and y spin components. The influence of substrate morphology on the Rashba band splitting at the Dirac point of graphene, has been theoretically investigated. More specifically, the possibility for this splitting to be caused by spin–orbit coupling (with the heavy metal substrate) was of a special interest to study. The model system consisted of a 4H-SiC (0 0 0 1)/graphene interface, with an intercalated metal layer (Ag and Au, respectively). These intercalating metal layers were built with two different types of morphologies; either flat or buckled (with different buckling positions). The results show that depending on the position of the buckled metal atom, the size of the bandgap and band splitting (at the Dirac point of graphene) will either increase (or decrease). Moreover, the enlargement of the buckling size was also shown to affect the electronic properties of graphene (i.e., by increasing the bandgap). The sizes of the bandgaps and band splitting for the different intercalating metals (Ag and Au), were also found to be different. Spin-projected band structures was also implemented in the present study, with the purpose to show the spin-texture of graphene. It was thereby shown that the spins pined to the x and y spin components for most of the cases. [ABSTRACT FROM AUTHOR]