Thickness dependence of spin-orbit torques generated by WTe2

We study current-induced torques in WTe2/permalloy bilayers as a function of WTe2 thickness. We measure the torques using both second-harmonic Hall and spin-torque ferromagnetic resonance measurements for samples with WTe2 thicknesses that span from 16 nm down to a single monolayer. We confirm the existence of an out-of-plane antidamping torque, and show directly that the sign of this torque component is reversed across a monolayer step in the WTe2. The magnitude of the out-of-plane antidamping torque depends only weakly on WTe2 thickness, such that even a single-monolayer WTe2 device provides a strong torque that is comparable to much thicker samples. In contrast, the out-of-plane field-like torque has a significant dependence on the WTe2 thickness. We demonstrate that this field-like component originates predominantly from the Oersted field, thereby correcting a previous inference drawn by our group based on a more limited set of samples.Comment: 8 pages, 8 figure

Проблеми та можливості споживання енергії в Україні

Проаналізовано споживання енергії в різних секторах економіки й подано модель визначення потенціалу зниження споживання енергії в Україні. Ключові слова: енергоефективність, енергозбереження, енергоємність, енергоспоживання, потенціал зменшення споживання енергії.Проанализированы потребления энергии в различных секторах экономики и представлена модель определения потенциала снижения потребления энергии в Украине. Ключевые слова: энергоэффективность, энергосбережение, энергоемкость, энергопотребление, потенциал уменьшения потребления энергии.The paper analyses energy consumption in different economic sectors and presents the model of determining the potential of reducing energy consumption in Ukraine. Keywords: energy efficiency, energy saving, energy intensity, energy waste, energy consumption, potential of reducing energy consumption

Occupational allergy to fruit flies (Drosophila melanogaster) in laboratory workers

OBJECTIVES: Drosophila melanogaster (the 'fruit fly') is commonly used in genetic research, but there is only one report of IgE-associated allergy in exposed workers. 4 newly identified cases prompted us to examine the extent of this problem in a university laboratory. Our aim in this study is to determine the prevalence and determinants of sensitisation to fruit flies in a population of exposed workers. METHODS: In a cross-sectional study, we surveyed 286 employees working in a department carrying out research involving D. melanogaster. Sensitisation was assessed by specific IgE measurement in serum and examined in relation to symptoms and to estimated exposure to fruit flies. RESULTS: The overall prevalence of specific sensitisation was 6% with a clear relationship to increasing frequency/intensity of exposure (p trend<0.001). Work-related eye/nose, chest or skin symptoms were reported by substantial proportions of participants but for most of these there was no evidence of specific sensitisation to fruit fly. The overall prevalence of any work-related symptoms and sensitisation was 2.4%, rising to 7.1% in those working in high exposure groups. CONCLUSIONS: We were able to demonstrate, for the first time, a clear exposure-response relationship between fruit fly exposure and specific sensitisation. Facilities housing fruit flies should carefully consider methods to reduce exposure levels in the workplace

Bis(μ-dithieno[3,2-b:2′,3′-d]thio­phene-2,6-dicarboxyl­ato-κ2 O 2:O 6)bis­[bis­(1,10-phenanthroline-κ2 N,N′)cobalt(II)] dimethyl­formamide disolvate

The asymmetric unit of the title compound, [Co2(C10H2O4S3)2(C12H8N2)4]·2C3H7NO, contains one half of the formula unit, with the rest generated by inversion. The cobalt ion sits in a slightly distorted octa­hedral environment and is ligated to four N atoms of two 1,10-phenanthroline molecules and to two O atoms of two dithieno[3,2-b:2′,3′-d]thio­phene-2,6-dicarb­oxy­l­ate anions. The anions act as bridges between the CoII centers

Spin-orbit torques in NbSe2_2/Permalloy bilayers

We present measurements of current-induced spin-orbit torques generated by NbSe$_2$, a fully-metallic transition-metal dichalcogenide material, made using the spin-torque ferromagnetic resonance (ST-FMR) technique with NbSe$_{2}$/Permalloy bilayers. In addition to the out-of-plane Oersted torque expected from current flow in the metallic NbSe$_{2}$ layer, we also observe an in-plane antidamping torque with torque conductivity $\sigma_{S} \approx 10^{3} (\hbar / 2e)$($\Omega$m)$^{-1}$ and indications of a weak field-like contribution to the out-of-plane torque oriented opposite to the Oersted torque. Furthermore, in some samples we also measure an in-plane field-like torque with the form $\hat{m} \times \hat{z}$, where $\hat{m}$ is the Permalloy magnetization direction and $\hat{z}$ is perpendicular to the sample plane. The size of this component varies strongly between samples and is not correlated with the NbSe$_{2}$ thickness. A torque of this form is not allowed by the bulk symmetries of NbSe$_{2}$, but is consistent with symmetry breaking by a uniaxial strain that might result during device fabrication.Comment: 14 pages, 3 figure