Strong SOC Research Articles

Photocytoxicity in vitro studies of ruthenium (II) complexes inducing cell death through targeting DNA

Photodynamic therapy (PDT) has been proven to be an important and effective therapy method with good spatial and temporal accuracy in clinical cancer treatment. Among many PDT candidates, Ru(II)-based compounds have received more attention due to their excellent photochemical and photophysical properties, high singlet oxygen (1O2) photogeneration, and DNA affinities. In this study, three ruthenium(II) complexes (RC1, RC2, RC3) have been designed by varying the aromatic plane area of the main ligand to adjust their 1O2 photogeneration, DNA affinities, DNA photodamage, and photocytoxicity. All complexes display no cytotoxicity in the dark against Hela, A549, HepG2, and BEL-7402 cells. RC1 displays no photocytotoxicity against all tumor cells. RC2 and RC3 showed high photocytotoxicity against BEL-7402 cells. The cellular uptake, cell migration, colonies assay, apoptosis analysis, and cell cycle analysis of RC2 and RC3 confirmed that the ruthenium(II) complexes might effectively enter the cancer cells, and lead to BEL-7402 cells apoptosis through DNA damage pathway. DNA photocleavage, DNA binding, and 1O2 measurement experiments demonstrated the DNA damage caused by RC2 and RC3 under light, compared to RC1, might be due to their high DNA affinities, large 1O2 quantum yields, and large lipophilicity by varying the aromatic plane area of the main ligand. Time dependent density functional theory (TDDFT) calculated results further show that two complexes exhibit the photocytotoxicity possibly via type II photoreaction mechanism because of the larger ΔS-T than O2 and strong SOC between Sn and Tm. Hence, rational design of ruthenium(II) complexes by increasing DNA affinities, 1O2 quantum yields and lipophilicity can be regarded as an effective approach for enhanced photodynamic therapy (PDT).

Electric Field Controlled Anisotropic Rashba Splitting in Janus Chromium Dichalcogenide Monolayers : A Computational Study based on Density Functional Theory

In this study, we explore the electronic structure of Janus Chromium Dichalcogenide monolayers CrXY (X ≠ Y = S, Se, Te) in the first Brillouin zone using Density Functional Theory. Due to the mirror symmetry break and strong SOC in the crystal structure of Janus Chromium Dichalcogenide monolayer, we discovered Rashba splitting at Γ points in the first Brillouin zone. We analyze this anisotropy of Rashba splitting using k∙p perturbation theory and group symmetry analysis. By giving the effect of external electric field, we manipulate the characteristics of Rashba splitting on the Janus Chromium Dichalcogenide monolayer. The manipulation of Rashba splitting by applying external electric field, shows that the Janus Chromium Dichalcogenide monolayers has the potential for spintronic devices.

Robust topological superconductivity in spin–orbit coupled systems at higher-order van Hove filling

Van Hove singularities in proximity to the Fermi level promote electronic interactions and generate diverse competing instabilities. It is also known that a nontrivial Berry phase derived from spin–orbit coupling can introduce an intriguing decoration into the interactions and thus alter correlated phenomena. However, it is unclear how and what type of new physics can emerge in a system featured by the interplay between van Hove singularities (VHSs) and the Berry phase. Here, based on a general Rashba model on the square lattice, we comprehensively explore such an interplay and its significant influence on the competing electronic instabilities by performing a parquet renormalization group analysis. Despite the existence of a variety of comparable fluctuations in the particle–particle and particle-hole channels associated with higher-order VHSs, we find that the chiral p±ip pairings emerge as two stable fixed trajectories within the generic interaction parameter space, namely the system becomes a robust topological superconductor. The chiral pairings stem from the hopping interaction induced by the nontrivial Berry phase. The possible experimental realization and implications are discussed. Our work sheds new light on the correlated states in quantum materials with strong spin–orbit coupling (SOC) and offers fresh insights into the exploration of topological superconductivity.

R/B-SecArch: A strong isolated SoC architecture based on red/black concept for secure and efficient cryptographic services

Cryptographic chips usually act as a secure base for information security systems and provide corresponding cryptographic services. Trusted execution environment (TEE) techniques for on-chip security have been widely proposed and effectively validated in academia and industry. However, existing mainstream TEEs still have certain security risks, especially in the face of emerging microarchitectural attacks. To address this issue, this paper proposes a strong isolation SoC architecture for high-security application requirements based on the red/black concept. Meanwhile, to provide efficient cryptographic services, we design an isolation interface that separates data and cryptographic tasks, and a cryptographic service descriptor that matches the isolation interface is defined. In addition, we designed a secure boot mechanism with OTP as the root of trust to ensure the system's power on security. Finally, we conduct performance tests and security analysis; the results show that the architecture can still provide efficient cryptographic services while ensuring security.

Reduction of carrier density and enhancement of the bulk Rashba spin-orbit coupling strength in Bi2Te3/GeTe superlattices

Featured with the large Rashba constant (αR ∼ 4.2 eVÅ) coupled with the ferroelectricity, GeTe has attracted much interest, proposing novel energy-efficient spintronic devices. However, those approaches are hampered by the high hole density of GeTe around 1020-1021 cm−3, which deteriorates both the ferroelectricity and the bulk Rashba effect of GeTe. To solve this problem, we have investigated the superlattices composed of Bi2Te3 and GeTe ([BT|GT] SL), the former of which is known as a topological insulator (TI) with typically n-type conduction and strong spin-orbit coupling. We have investigated the magnetotransport properties of 25 [BTx|GTy]z SLs with varying thicknesses (x, y: the thickness in the multiples of the unit cell of the respective layer) of each layer and the repetition number (z) systematically. We have observed a minimum carrier density of 5.7 × 1019 cm−3 in [BT6|GeTe6]6 superlattice sample smaller than that (∼4.4 ×1020 cm−3) of GeTe single film by an order. In addition, we have found that some [BT|GT] SLs with reduced carrier density have a larger Rashba constant compared to that of a single GeTe film. This is explained by the change of the spin polarization which can be modulated by the Fermi level in the Rashba band. These results provide a viable way to realize robust ferroelectricity and strong SOC in GeTe-related material systems simultaneously.

Electronic structure and resonant inelastic x-ray scattering in GaTa4Se8

We have investigated the electronic structure of the lacunar spinel compound GaTa4Se8 within the density-functional theory (DFT) using the generalized gradient approximation while taking into account strong Coulomb correlations (GGA+U) in the framework of the fully relativistic spin-polarized Dirac linear muffin-tin orbital band-structure method. GaTa4Se8 can be classified as a Mott insulator since it was expected to be metallic from GGA band structure calculations in contradiction with the resistivity and optical measurements. Strong SOC splits the t2g-type manifold into a lower jeff = 3/2 quartet and an upper jeff = 1/2 doublet. The empty jeff = 1/2 band is well separated from the jeff = 3/2 one and almost completely given by linear combinations of d5/2 states. The partly filled jeff = 3/2 band is dominated by d3/2 states with some weight of d5/2 ones and consists of two groups of bands separated by an energy gap. The low energy jeff = 3/2 band situated at the Fermi level is very narrow, therefore even a small Hubbard U opens the energy gap. We have investigated theoretically the resonant inelastic x-ray scattering (RIXS) spectra at the Ta L2,3 edges. The calculated results are in good agreement with experimental data. We have found that the best agreement between the theory and experiment in the value of the Hubbard energy gap and RIXS spectra at the Ta L2,3 edges can be achieved for Ueff = 1.0 eV. The experimentally measured RIXS spectrum of GaTa4Se8 at the Ta L3 edge in addition to the elastic scattering peak at 0 eV possesses a sharp feature below 1 eV corresponding to transitions within the Ta t2g levels. The excitation located from 1 eV to 2 eV is due to t2g→eg transitions. The third wide very intensive structure from 2.8 eV up to 12 eV is almost completely derived from ligand-to-ligand charge transfer excitations. Such a situation is quite unique for the RIXS spectra in transition 5d metal systems. The origin of this dominant contribution as well as the electronic correlation in GaTa4Se8 is a consequence of its peculiar crystal structure which forms tetrahedral Ta4 clusters with very small intracluster Ta–Ta and Ta–Se distances and rather large distances between the Ta4 clusters. It results in the formation of localized electronic states and extremely strong Ta 5d - Se 4p hybridization which creates 5dSe states with high density of states. Such hybridization is much stronger in comparison with the corresponding 5d - O 2p hybridization in 5d transition metal oxides due to more extended Se 4p wave functions in comparison with oxygen 2p ones.

Latent change models of lifestyle in acute coronary syndrome patients: Are lifestyle changes associated with resilience changes?

This study aimed to examine the role of resilience resources in patients' lifestyle changes after the first Acute Coronary event. 275 Italian patients (84.0% men; mean age = 57.5, SD = 7.9) participated in a longitudinal study. Resilience resources (Self-esteem, Dispositional Optimism, Sense of Coherence - SOC, General and Disease-specific Self-efficacy), and lifestyles (diet, physical activity, and smoking) were assessed twice (at baseline and after 6months). Path analysis using latent change models was performed to model the combined effect of levels and changes of the resilience resources over lifestyle changes. Patients with strong SOC at baseline were less prone to smoke and more prone to decrease smoking; enhancement in SOC was associated with a smoking decrease. High Disease-specific Self-efficacy at baseline was associated with an improvement in all lifestyles; enhancement in Disease-specific Self-efficacy predicted an increase in physical activity. Findings underline the need to design psychological interventions that promote patients' Disease-specific Self-efficacy and SOC.

Intrinsic Analysis of Thermally Activated Delayed Fluorescence (TADF) for Ag(I) Complex Based on the Path Integral Approach: Origin of the Effective Spin-Flipping Channel and Vibrational Spin-Orbit Coupling Effect.

In order to design new Ag(I)-based materials for thermally activated delayed fluorescence (TADF), it is vital to develop a detailed understanding of the current best performing materials. The quantitative predictions of the photophysical processes of the Ag(dmp)(P2-nCB) TADF complex are calculated using time-dependent density functional theory (TD-DFT) combined with the path integral approach for dynamics including the Herzberg-Teller effects. All calculated results are in good agreement with the experimentally available data, demonstrating the validity of our applied theoretical approach. Analysis of ETS-NOCV (extended transition state natural orbital for chemical valence) shows that there is a weak bond interaction dominated by electrostatic interactions and accompanied by some covalent components between Ag(I) and dmp ligands due to the introduction of the strongly electron-donating negatively charged P2-nCB ligand, thus giving a small energy separation between the lowest singlet S1 and triplet T1 states of ΔE(S1 - T1) ≈ 532 cm-1. The SOC strongly depends on the geometrical alteration caused by the molecular "promotion" vibrations. Our study has revealed that a few "promotion" vibrational modes, that is, ω46 and ω227, effectively induce the strong SOC between S1 and T1 and speed up the reverse intersystem crossing (RISC) process dramatically. The computed kRISC value is 1.19 × 107 s-1 for the solid phase at 300 K, which are about 5 orders of magnitude larger than the mean phosphorescence rate, kP = 9.56 × 102 s-1, and it is also far larger than ISC k0ISC = 7.84 × 102 s-1 rates from T1 to S0. The S1 state thus can be an efficient thermal repopulation from the T1 state by the RISC pathway. Finally, we also note that the diabatic vibration coupling triplet pair T1/T2 will also be important for efficient and practical RISC. Our investigation will be of great utility toward designing and improving the Ag(I)-based TADF complexes.

Giant photoinduced inverse spin Hall effect of the surface states in three dimensional topological insulators Bi2Te3 with different thickness.

The photoinduced inverse spin Hall effect (PISHE) has been studied in three dimensional (3D) topological insulator (TI) Bi2Te3 thin films with different thicknesses (3, 5, 12 and 20 quintuple layer (QL)). The sign of the PISHE current flips only once in the 3- and 20-QL Bi2Te3 films, but it flips three times in the 5-, 7- and 12-QL samples. The three-times sign flip is due to the superposition of the PISHE current of the top and bottom surface states in Bi2Te3 films. By analyzing the x-ray photoelectron spectroscopy (XPS) of the Bi2Te3 films, we find that the top surface of the 3- and 20-QL Bi2Te3 films are severely oxidized, leading to only one sign flip in the PISHE. The PISHE contributed by the top and bottom surface states in Bi2Te3 films have been successfully separated by fitting a theoretical model to the PISHE current. The impact of the bulk states on PISHE current has been determined. The PISHE current is also measured at different light powers, and all the measurement results are in good agreement with the theoretical model. In addition, it is found that the PISHE current in Bi2Te3 films grown on Si substrate is more than two orders larger than that grown on SrTiO3 substrates, which can be attributed to the larger absorption coefficient for Bi2Te3/Si samples. It is revealed that the PISHE current in 3D TI Bi2Te3 is as large as 140 nA/W in the 3-QL Bi2Te3 film grown on Si substrate, which is more than one order larger than that reported in GaAs/AlGaAs heterojunction (about 2 nA/W) and GaN/AlGaN heterojunction (about 1.7 nA/W). The giant PISHE current demonstrates that the TIs with strong SOC may have good application prospects in spintronic devices with high spin-to-charge conversion efficiency.

Patterns of Suicide Ideation Across Eight Countries in Four Continents During the COVID-19 Pandemic Era: Repeated Cross-sectional Study.

BackgroundThe COVID-19 pandemic and countries’ response measures have had a globally significant mental health impact. This mental health burden has also been fueled by an infodemic: an information overload that includes misinformation and disinformation. Suicide, the worst mental health outcome, is a serious public health problem that can be prevented with timely, evidence-based, and often low-cost interventions. Suicide ideation, one important risk factor for suicide, is thus important to measure and monitor, as are the factors that may impact on it.ObjectiveThis investigation had 2 primary aims: (1) to estimate and compare country-specific prevalence of suicide ideation at 2 different time points, overall and by gender and age groups, and (2) to investigate the influence of sociodemographic and infodemic variables on suicide ideation.MethodsA repeated, online, 8-country (Canada, the United States, England, Switzerland, Belgium, Hong Kong, Philippines, and New Zealand), cross-sectional study was undertaken with adults aged ≥18 years, with measurement wave 1 conducted from May 29, 2020 to June 12, 2020 and measurement wave 2 conducted November 6-18, 2021. Self-reported suicide ideation was derived from item 9 of the Patient Health Questionnaire-9 (PHQ-9). Age-standardized suicide ideation rates were reported, a binomial regression model was used to estimate suicide ideation indication rates for each country and measurement wave, and logistic regression models were then employed to relate sociodemographic, pandemic, and infodemic variables to suicide ideation.ResultsThe final sample totaled 17,833 adults: 8806 (49.4%) from measurement wave 1 and 9027 (50.6%) from wave 2. Overall, 24.2% (2131/8806) and 27.5% (2486/9027) of participants reported suicide ideation at measurement waves 1 and 2, respectively, a difference that was significant (P<.001). Considerable variability was observed in suicide ideation age-standardized rates between countries, ranging from 15.6% in Belgium (wave 1) to 42.9% in Hong Kong (wave 2). Frequent social media usage was associated with increased suicide ideation at wave 2 (adjusted odds ratio [AOR] 1.47, 95% CI 1.25-1.72; P<.001) but not wave 1 (AOR 1.11, 95% CI 0.96-1.23; P=.16). However, having a weaker sense of coherence (SOC; AOR 3.80, 95% CI 3.18-4.55 at wave 1 and AOR 4.39, 95% CI 3.66-5.27 at wave 2; both P<.001) had the largest overall effect size.ConclusionsSuicide ideation is prevalent and significantly increasing over time in this COVID-19 pandemic era, with considerable variability between countries. Younger adults and those residing in Hong Kong carried disproportionately higher rates. Social media appears to have an increasingly detrimental association with suicide ideation, although having a stronger SOC had a larger protective effect. Policies and promotion of SOC, together with disseminating health information that explicitly tackles the infodemic’s misinformation and disinformation, may importantly reduce the rising mental health morbidity and mortality triggered by this pandemic.

Multi-predictor mapping of soil organic carbon in the alpine tundra: a case study for the central Ecuadorian p\xe1ramo

BackgroundSoil organic carbon (SOC) affects essential biological, biochemical, and physical soil functions such as nutrient cycling, water retention, water distribution, and soil structure stability. The Andean páramo known as such a high carbon and water storage capacity ecosystem is a complex, heterogeneous and remote ecosystem complicating field studies to collect SOC data. Here, we propose a multi-predictor remote quantification of SOC using Random Forest Regression to map SOC stock in the herbaceous páramo of the Chimborazo province, Ecuador.ResultsSpectral indices derived from the Landsat-8 (L8) sensors, OLI and TIRS, topographic, geological, soil taxonomy and climate variables were used in combination with 500 in situ SOC sampling data for training and calibrating a suitable predictive SOC model. The final predictive model selected uses nine predictors with a RMSE of 1.72% and a R2 of 0.82 for SOC expressed in weight %, a RMSE of 25.8 Mg/ha and a R2 of 0.77 for the model in units of Mg/ha. Satellite-derived indices such as VARIG, SLP, NDVI, NDWI, SAVI, EVI2, WDRVI, NDSI, NDMI, NBR and NBR2 were not found to be strong SOC predictors. Relevant predictors instead were in order of importance: geological unit, soil taxonomy, precipitation, elevation, orientation, slope length and steepness (LS Factor), Bare Soil Index (BI), average annual temperature and TOA Brightness Temperature.ConclusionsVariables such as the BI index derived from satellite images and the LS factor from the DEM increase the SOC mapping accuracy. The mapping results show that over 57% of the study area contains high concentrations of SOC, between 150 and 205 Mg/ha, positioning the herbaceous páramo as an ecosystem of global importance. The results obtained with this study can be used to extent the SOC mapping in the whole herbaceous ecosystem of Ecuador offering an efficient and accurate methodology without the need for intensive in situ sampling.

Order out of chaos: Sense of coherence and the mediating role of coping resources in explaining mental health during COVID-19 in 7 countries

In the midst of the COVID-19 pandemic and the universal chaos created by it, this study explores the role of sense of coherence (Soc, Antonovsky, 1979) and how it enables coping with a stressful situation and staying well. SOC is a generalized orientation which allows one to perceive the world as comprehensible, manageable, and meaningful. In an attempt to understand ‘how does the SOC work’ we employed the salutogenic assumption that a strong SOC allows one to reach out in any given situation and find those resources appropriate to the specific stressor. Thus, we hypothesized that the positive impact of SOC on mental health outcomes would be mediated through coping resources that are particularly salient in times of crisis. One resource is related to the micro level (perceived family support) and the other concerns the macro level (trust in leaders and social-political institutions). Data collection was conducted in different countries during May–June 2020 via online platforms. The data included 7 samples of adult participants (age 18–90) from Israel (n ​= ​669), Italy (n ​= ​899), Spain (n ​= ​476), Germany (n ​= ​708), Austria (n ​= ​1026), Switzerland (n ​= ​147), and the U.S. (n ​= ​506). The questionnaires included standard tools (MHC-SF, SOC-13) as well as questionnaires of perceived family support and trust that were adapted to the pandemic context. As expected, SOC was associated with mental health in all the samples. Perceived family support and trust in leaders and social-political institutions mediated the relationships between SOC and mental health, controlling for age, gender, and level of financial risk. It appears that SOC has a universal meaning, not limited by cultural and situational characteristics. The discussion focuses on the theoretical, social, and political applications of the salutogenic model – and its core concept of SOC – in the context of coping with a global pandemic across different cultural contexts and countries.

Influence of thickness on current-induced magnetization switching in L10-FePt single layer* *Project supported by the National Key Research and Development Program of China (Grant No. 2019YFB2005801), the National Natural Science Foundation of China (Grant Nos. 51971027, 51731003, 51971023, 51927802, and 51971024), and the Fundamental Research Funds for the Central Universities, China (Grant No. FRF-TP-19-001A3).

The thickness dependent spin–orbit torque (SOT) in an L10-FePt single layer is investigated in this work. As the thickness increases from 8 nm to 16 nm, the magnetization switching ratio in the L10-FePt film with higher chemical ordering becomes smaller. It is noted that compared with 3-nm-thick L10-FePt film, 8-nm-thick L10-FePt film can switch much magnetization with the increase of chemical ordering. When the FePt film is thick enough, the SOT in FePt is closely related to the L10-ordered structure, which indicates a bulk nature. Therefore, the disordering plays an important role in the magnetization switching only for the ultra-thin FePt films, while the structural gradient may play an important role for thicker films. However, both of the two mechanisms cannot fully explain the process of magnetization switching and the spin current generation. Although many factors influence SOT, here in this work we emphasize only the bulk nature of strong SOC in L10-FePt through density functional theory calculations, which should generate large spin current due to spin Hall effect.

The genetic background of the associations between sense of coherence and mental health, self-esteem and personality

PurposeSense of coherence (SOC) represents coping and can be considered an essential component of mental health. SOC correlates with mental health and personality, but the background of these associations is poorly understood. We analyzed the role of genetic factors behind the associations of SOC with mental health, self-esteem and personality using genetic twin modeling and polygenic scores (PGS).MethodsInformation on SOC (13-item Orientation of Life Questionnaire), four mental health indicators, self-esteem and personality (NEO Five Factor Inventory Questionnaire) was collected from 1295 Finnish twins at 20–27 years of age.ResultsIn men and women, SOC correlated negatively with depression, alexithymia, schizotypal personality and overall mental health problems and positively with self-esteem. For personality factors, neuroticism was associated with weaker SOC and extraversion, agreeableness and conscientiousness with stronger SOC. All these psychological traits were influenced by genetic factors with heritability estimates ranging from 19 to 66%. Genetic and environmental factors explained these associations, but the genetic correlations were generally stronger. The PGS of major depressive disorder was associated with weaker, and the PGS of general risk tolerance with stronger SOC in men, whereas in women the PGS of subjective well-being was associated with stronger SOC and the PGSs of depression and neuroticism with weaker SOC.ConclusionOur results indicate that a substantial proportion of genetic variation in SOC is shared with mental health, self-esteem and personality indicators. This suggests that the correlations between these traits reflect a common neurobiological background rather than merely the influence of external stressors.

Association between forest and greenspace walking and stress-coping skills among workers of Tsukuba Science City, Japan: A cross-sectional study

ObjectivesRecently, “sense of coherence” (SOC) as a concept of stress-coping, has been gaining considerable attention. Although many studies have investigated the factors related to strong SOC, we found little evidence about the associations between SOC and habits that are easy to perform in everyday life. The aim our study was to examine the prevalence of workers who engage in forest walking and greenspace walking and examine their association with SOC score. Study designA cross-sectional study. MethodsAn anonymous, self-report web questionnaire was conducted in November 2017. The study population included 19481 workers belonging to the Tsukuba Science City Network and data of 6466 participants (3965 men and 2501 women) were analyzed. ResultsThe percentage of participants who engage in forest and greenspace walking at least once a year were 55.9% and 75.9%, respectively. Associations between forest/greenspace walking and SOC score were calculated using Chi-squared tests. Multinomial logistic regression analyses with SOC score group (strong/middle/weak) as a dependent variable and forest/greenspace walking as explanatory variables were performed. Statistically significant positive associations were observed between strong SOC and those who engaged in forest/greenspace walking after adjusting for socioeconomic factors. The odds ratios for strong SOC were 3.65 (95% CI ​= ​1.70–7.85) for forest walking at least once a week and 2.12 for greenspace walking (95% CI ​= ​1.54–2.92) at least once a week. ConclusionsOur findings suggested that forest/greenspace walking may enhance workers’ stress-coping skills.

Sense of coherence and impact of oral health on quality of life in adults and elderly in Southern Brazil.

This cross-sectional study aimed to investigate the association between the Sense of Coherence and impact of oral health on the quality of life. Was conducted with a sample of 720 individuals of both sexes, between the ages of 50 and 74 years, selected through multistage proportional random sampling. The data collection instruments used were: short version of the Sense of Coherence Scale (SOC-13), Oral Impacts on Daily Performances (OIDP) questionnaire, oral clinical examination and questionnaire containing socio demographic and use of dental services information. Bivariate and multivariate analyses were performed through Poisson regression adjusted for robust variance, with level of significance p < 0.05. Oral impacts were reported by 416 participants (57.8%). In the adjusted model, those with strong SOC were more likely of not having any impact when compared with individuals with weak SOC (PR=1.30). Need for dental prosthesis was also associated with the outcome, individuals who did not require prosthesis had less impact (PR=1.50). The findings showed that SOC is associated with OIDP, supporting the hypothesis that individuals with strong SOC present a lower impact of oral health on the quality of life, suggesting that SOC is a determinant that can provide protection against that impact.

Microscopic origin of spin-orbit torque in ferromagnetic heterostructures: A first-principles approach

We present an ab initio based theoretical framework which elucidates the origin of the spin-orbit torque (SOT) in normal-metal (NM)/ferromagnet (FM) heterostructures. The SOT is decomposed into two contributions, namely, spin-Hall and the spin-orbital components. We find that (i) the fieldlike (FL) SOT is dominated by the spin-orbital component and (ii) both components contribute to the dampinglike (DL) torque with comparable magnitude in the limit of thick Pt film. The contribution of the spin-orbital component to the DL-SOT is present only for NMs with strong SOC coupling strength. We demonstrate that the FL-SOT can be expressed in terms of the nonequilibrium spin-resolved orbital moment accumulation. The calculations reveal that the experimentally reported oxygen-induced sign reversal of the FL-SOT in Pt/Co bilayers is due to the significant reduction of the majority-spin orbital moment accumulation on the interfacial NM atoms.

Robust band gap topological insulators of SbS and SbSH

Using first-principles calculations, we predicted a group of excellent two-dimensional (2D) topological materials of SbS and SbSH monolayers with global gaps of 152 meV for SbS and up to 400 meV for SbSH. In most of the 2D topological insulators, the main components of band structures near the Fermi level are mostly orbitals of heavy elements with a strong SOC effect. But for SbS, the bands near Fermi level mainly consist of px and py orbitals of S, and for SbSH, the bands near Fermi level mainly consist of pxy orbitals of Sb instead of S. The bonding effect between Sb and S or SH removes the pz orbital of Sb and S, and leaves behind only pxy orbitals of Sb and S near the Fermi level. The S atoms and SH groups act as an orbital filter to critically select the orbital composition around the Fermi level. According to the orbital-filtering mechanism proposed by Miao Zhou and a four-band model of topological phase in a hexagonal lattice, SbS and SbSH are topological insulators. The topological characteristic of SbS and SbSH monolayers are confirmed by Z2 = 1 topological invariant and topological edge states. Our study adds two novel members to the 2D topological family.

Gate control of quantum dot-based electron spin–orbit qubits

We investigate theoretically the coherent spin dynamics of gate control of quantum dot-based electron spin–orbit qubits subjected to a tilted magnetic field under electric-dipole spin resonance (EDSR). Our results reveal that Rabi oscillation of qubit states can be manipulated electrically based on rapid gate control of SOC strength. The Rabi frequency is strongly dependent on the gate-induced electric field, the strength and orientation of the applied magnetic field. There are two major EDSR mechanisms. One arises from electric field-induced spin–orbit hybridization, and the other arises from magnetic field-induced energy-level crossing. The SOC introduced by the gate-induced electric field allows AC electric fields to drive coherent Rabi oscillations between spin-up and -down states. After the crossing of the energy-levels with the magnetic field, the spin-transfer crossing results in Rabi oscillation irrespective of whether or not the external electric field is present. The spin–orbit qubit is transferred into the orbit qubit. Rabi oscillation is anisotropic and periodic with respect to the tilted and in-plane orientation of the magnetic field originating from the interplay of the SOC, orbital, and Zeeman effects. The strong electrically-controlled SOC strength suggests the possibility for scalable applications of gate-controllable spin–orbit qubits.

Sense of Coherence and Quality of Life in Caregivers of Children With Autism Spectrum Disorders

Abstract Date Presented 4/7/2016 Sense of Coherence (SOC) proposes that when people have an understanding of a challenge, tools to manage it, and a sense of purpose, they are able to cope. Associations were found in this study between a strong SOC in caregivers of children with autism spectrum disorder and a better quality of life. Primary Author and Speaker: Maureen Russell Contributing Authors: Carol Baldwin, Stuart Quan, Darya McClain, Christopher Smith, Nicole Matthews