The spin Hall effect and its inverse effect, caused by the spin orbit interaction, provide the interconversion between spin current and charge current. Since the effects make it possible to generate and manipulate spin current electrically, how to realize the large effects is an important issue in both physics and applications. To do so, materials with heavy elements, which have strong spin orbit interaction, have been examined so far. Here, we propose a new mechanism to enhance the spin Hall effect without heavy elements, \ie surface roughness in metallic thin films. We examine Cu and Al thin films with surface roughness and find that they give the spin Hall effect comparable to that in bulk Au. We demonstrate that the spin Hall effect induced by surface roughness has the side jump contribution but not skew scattering.Comment: 5 pages, 4 figure

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The work function (WF) is of crucial importance to dominate the carrier transport properties of the Ge-Sb-Te based interfaces. In this letter, the electrostatic force microscopy is proposed to extract the WF of Ge2Sb2Te5 (GST) films with high spatial and energy resolution. The measured WF of as-deposited amorphous GST is 5.34 eV and decreases drastically after the amorphous GST is crystallized by annealing or laser illumination. A 512 × 512 array 2D-WF map is designed to study the WF spatial distribution and shows a good consistency. The WF contrast between a-GST and c-GST is ascribed to band modulation, especially the modification of electron affinity including the contribution of charges or dipoles. Then, the band alignments of GST/n-Si heterostructures are obtained based on the Anderson's rule. Due to the band modulation, the I-V characteristics of a-GST/Si heterojunction and c-GST/Si heterojunction are very different from each other. The quantitative relationship is calculated by solving the Poisson's equation, which agrees well with the I-V measurements. Our findings not only suggest a way to further understand the electrical transport properties of Ge-Sb-Te based interfaces but also provide a non-touch method to distinguish crystalline area from amorphous matrix with high spatial resolution.

Sevoflurane is associated with a relatively high incidence of emergence agitation (EA) in children. Prophylactic treatment, including midazolam, dexmedetomidine, ketamine, fentanyl and propofol, has been used to prevent EA. However, the question of which prophylactic treatment should be preferred to decrease the incidence of EA is still unclear. We conducted a network meta-analysis of randomized controlled trials to investigate the comparative efficacy of midazolam, dexmedetomidine, ketamine, fentanyl, and propofol for the prevention of sevoflurane-related EA in children. First, we used the odds ratios and 95% confidence interval as effect size. The results revealed that dexmedetomidine 0.19 (0.14-0.27), midazolam 0.22 (0.07-0.60), ketamine 0.28 (0.16-0.51), propofol 0.23 (0.10-0.53), and fentanyl 0.25 (0.17-0.36) led to a significant reduction of the incidence of EA when compared with placebo. With placebo as the standard of comparison, the degree of incoherence (a measure of how closely the entire network fits together) was small (ω = 8.66728e-08). The logor were dexmedetomidine -1.75 (-2.11 to -1.39), midazolam -1.07 (-1.54 to -0.60), ketamine -1.292 (-1.92 to -0.66), and fentanyl -1.13 (-1.56 to -0.70). When compared with dexmedetomidine, the logor were placebo 1.75 (1.39-2.11), midazolam 0.67 (0.09-1.25), ketamine 0.45 (-0.25-1.15), propofol 0.75 (0.19-1.31), and fentanyl 0.617 (0.13-1.11). When compared with ketamine, the logor were placebo 1.29 (0.66-1.92), midazolam 0.22 (-0.56 to 1.00), dexmedetomidine -0.45 (-1.15-0.25); propofol 0.29 (-0.45-1.03); and fentanyl 0.16 (-0.59-0.92). The study that showed dexmedetomidine, midazolam, ketamine, propofol, and fentanyl could significantly decrease the incidence of EA when compared with placebo. One interesting finding of this network meta-analysis is that dexmedetomidine might be the best choice to prevent EA. However, there is weak evidence that dexmedetomidine is better than ketamine for the prevention of sevoflurane-related EA in children. As a result, more studies are needed to compare dexmedetomidine with ketamine.