We present self-energy calculations for Hg chalcogenides (HgX, X=S, Se, and Te) with inverted band structures using an explicit spin-dependent formulation of the GW approximation. Spin-orbit coupling is fully taken in...
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We present self-energy calculations for Hg chalcogenides (HgX, X=S, Se, and Te) with inverted band structures using an explicit spin-dependent formulation of the GW approximation. Spin-orbit coupling is fully taken into account in calculating the single-particle Green function G and the screened interaction W. We have found, apart from an upward shift of the occupied conductionlike Γ6 state by about 0.7 eV, an enhancement of spin-orbit splitting by about 0.1 eV, in good agreement with experiment. This renormalization originates mainly from spin-orbit induced changes in G rather than W, which is affected only little by spin-orbit coupling.
In this study, GaN nanocolumns was fabricated through RF-plasma assisted molecular beam epitaxy on sapphire substrate. SEM was used for nanocolumn structure analysis. Photoluminescence image of InGaN-single quantum we...
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ISBN:
(纸本)9781457705328
In this study, GaN nanocolumns was fabricated through RF-plasma assisted molecular beam epitaxy on sapphire substrate. SEM was used for nanocolumn structure analysis. Photoluminescence image of InGaN-single quantum well at the top of each nanocolumn was detected at each near-field scanning optical microscopy (NSOM)scanning point. The intensity was observed to decrease exponentially which was attributed to Anderson localization.
The need for large-scale electronic structure calculations arises recently in the field of material physics, and efficient and accurate algebraic methods for large simultaneous linear equations become greatly importan...
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The need for large-scale electronic structure calculations arises recently in the field of material physics, and efficient and accurate algebraic methods for large simultaneous linear equations become greatly important. We investigate the generalized shifted conjugate orthogonal conjugate gradient method, the generalized Lanczos method, and the generalized Arnoldi method. They are the solver methods of large simultaneous linear equations of the one-electron Schrödinger equation and map the whole Hilbert space to a small subspace called the Krylov subspace. These methods are applied to systems of fcc Au with the NRL tight-binding Hamiltonian [F. Kirchhoff et al., Phys. Rev. B 63, 195101 (2001)]. We compare results by these methods and the exact calculation and show them to be equally accurate. The system size dependence of the CPU time is also discussed. The generalized Lanczos method and the generalized Arnoldi method are the most suitable for the large-scale molecular dynamics simulations from the viewpoint of CPU time and memory size.
The magnetic coupling between Fe and Cu moments in the charge-disproportionated CaCu3Fe4O12 is studied by neutron powder diffraction, x-ray absorption, and magnetic circular dichroism measurements. The magnetic moment...
The magnetic coupling between Fe and Cu moments in the charge-disproportionated CaCu3Fe4O12 is studied by neutron powder diffraction, x-ray absorption, and magnetic circular dichroism measurements. The magnetic moments of the B-site Fe are coupled antiferromagnetically with those of the A′-site Cu, and the Fe3+ and Fe5+ spins at the B site align ferromagnetically. The orbital contribution of the magnetic moment for Fe is significant and appears to stabilize the ferrimagnetic structure of charge-disproportionated CaCu3Fe4O12.
Polarization-entangled photon pairs have been widely used as a light source of quantum communication. The polarization-entangled photon pairs are generally obtained at the crossing points of the light cones that are g...
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Polarization-entangled photon pairs have been widely used as a light source of quantum communication. The polarization-entangled photon pairs are generally obtained at the crossing points of the light cones that are generated from a type-II nonlinear crystal. However, it is hard to pick up the photon pairs coming out from the crossing points because of their invisible wavelength and low intensity. In our previous work, we succeeded in generating polarization-entangled photon pairs by overlapping two light paths for the photon-pair generation. The photon pairs could be entangled in all of the generated photon pairs without clipping the crossing points, even with some difficulty in its alignment to overlap the two light paths. In this paper, we have developed an optical system which generates polarization-entangled photon pairs using a beamlike photon pair, without the difficulty in alignment. The measured results show that the photon pairs generated in the system are entangled in their polarizations.
The self-diffraction effect was used to improve temporal contrast of femtosecond pulse by about four-order of magnitudes. This self-diffraction effect was also used to measure a 55fs pulse based on the self-referenced...
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ISBN:
(纸本)9780977565771
The self-diffraction effect was used to improve temporal contrast of femtosecond pulse by about four-order of magnitudes. This self-diffraction effect was also used to measure a 55fs pulse based on the self-referenced spectral interferometry method.
Session fixation is a technique for obtaining the visitor's session identifier (SID) by forcing the visitor to use the SID supplied by the attacker. The attacker who obtains the victim's SID can masquerade as ...
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