Control of Spin Diffusion and Suppression of the Hanle Effect by the Coexistence of Spin and Valley Hall Effects

In addition to spin, electrons in many materials possess an additional pseudo-spin degree of freedom known as 'valley'. In materials where the spin and valley degrees of freedom are weakly coupled, they can be both excited and controlled independently. In this work, we study a model describing the interplay of the spin and valley Hall effects in such two-dimensional materials. We demonstrate the emergence of an additional longitudinal neutral current that is both spin and valley polarized. The additional neutral current allows to control the spin density by tuning the magnitude of the valley Hall effect. In addition, the interplay of the two effects can suppress the Hanle effect, that is, the oscillation of the nonlocal resistance of a Hall bar device with in-plane magnetic field. The latter observation provides a possible explanation for the absence of the Hanle effect in a number of recent experiments. Our work opens also the possibility to engineer the conversion between the valley and spin degrees of freedom in two-dimensional materials.Comment: 15 pages, 2 figure

Asymptotic behavior of multiple solutions for quasilinear Schrödinger equations

This paper establishes the multiplicity of solutions for a class of quasilinear Schrödinger elliptic equations: −∆u + V(x)u − 2 ∆(u 2 )u = f(x, u), x ∈ R 3 where V(x) : R3 → R is a given potential and γ > 0. Furthermore, by the variational argument and L ∞-estimates, we are able to obtain the precise asymptotic behavior of these solutions as γ → 0

The Empirical Analysis on the Carbon Emission Transfer by Sino-EU Merchandise Trade

By using input-output analysis method, this paper analyses the China and European Union’s corresponding transfer amount of carbon emissions caused by Sino-EU trade in 2002, 2007 and 2012.Furthermore, the influence degree of scale, structure and intensity on the amount of carbon emission transfer of China and European Union in a specific period of time was analyzed by using the method of LMDI. The result shows that there exists carbon emissions transfer from European Union to China. Scale effect always has a positive influence on the transferred amount of Chinese and European carbon emissions during the study period. The negative effect of structure to the transferred carbon emissions of China is weakening and the effect of intensity to the transferred carbon emissions of China is from the positive influence to negative one. For the EU, the effect of structure and intensity remain relatively stable state

The significance of self-annealing in two-phase alloys processed by high-pressure torsion

The Zn-22% Al eutectoid alloy and the Pb-62% Sn eutectic alloy were processed by high-pressure torsion (HPT) over a range of experimental conditions. Both alloys exhibit similar characteristics with significant grain refinement after processing by HPT but with a reduction in the hardness values by comparison with the initial unprocessed conditions. After storage at room temperature for a period of time, it is shown that the microhardness of both alloys gradually recovers to close to the initial unprocessed values. Electron backscatter diffraction (EBSD) measurements on the Pb-Sn alloy suggest that the self-recovery behaviour is correlated with the fraction of high-angle grain boundaries (HAGBs) after HPT processing. Thus, high fractions of HAGBs occur immediately after processing and this favours grain boundary migration and sliding which is important in the self-annealing and recovery process. Conversely, the relatively lower fractions of HAGBs occurring after annealing at room temperature are not so conducive to easy migration and slidin

Microstructures and mechanical properties of pure tantalum processed by high-pressure torsion

A body-centred cubic (BCC) structure metal, tantalum, was processed by high- pressure torsion (HPT) at room temperature with different numbers of rotations. The microstructural evolution was studied by electron backscatter diffraction (EBSD). The grain sizes were significantly refined at the disk edge area in the early stages of deformation (N = 0.5) but tended to attain saturation after the numbers of rotations was increased to N = 5. As the deformation continued, some coarse grains appeared in the disk edge areas and it appeared that there was structural recovery at the expense of grain boundary migration in the tantalum during HPT processing. Microhardness measurements showed the hardness gradually evolved towards a more homogenized level across the disk surfaces as the numbers of rotations increased. The hardness level after N = 10 turns was slightly lower than after N = 5 turns, thereby indicating the occurrence of a recovery process after 5 turn

Contrastive Analysis of the Raman Spectra of Polychlorinated Benzene: Hexachlorobenzene and Benzene

Detection of persistent pollutants such as polychlorinated benzene in environment in trace amounts is challenging, but important. It is more difficult to distinguish homologues and isomers of organic pollutantd when present in trace amounts because of their similar physical and chemical properties. In this work we simulate the Raman spectra of hexachlorobenzene and benzene, and figure out the vibration mode of each main peak. The effect on the Raman spectrum of changing substituents from H to Cl is analyzed to reveal the relations between the Raman spectra of homologues and isomers of polychlorinated benzene, which should be helpful for distinguishing one kind of polychlorinated benzene from its homologues and isomers by surface enhanced Raman scattering

Asymptotic behavior of multiple solutions for quasilinear Schrödinger equations

This paper establishes the multiplicity of solutions for a class of quasilinear Schrödinger elliptic equations: −∆u + V(x)u − 2 ∆(u 2 )u = f(x, u), x ∈ R 3 where V(x) : R3 → R is a given potential and γ > 0. Furthermore, by the variational argument and L ∞-estimates, we are able to obtain the precise asymptotic behavior of these solutions as γ → 0