A near-field study on the transition from localized to propagating plasmons on 2D nano-wedges

In this manuscript we report on a near-feld study of two-dimensional plasmonic gold nano-wedges using electron energy loss spectroscopy in combination with scanning transmission electron microscopy, as well as discontinuous Galerkin time-domain computations. With increasing nano-wedge size, we observe a transition from localized surface plasmons on small nano-wedges to non-resonant propagating surface plasmon polaritons on large nano-wedges. Furthermore we demonstrate that nano-wedges with a groove cut can support localized as well as propagating plasmons in the same energy range

Science through a tribal lens: A group-based account of polarization over scientific facts

Previous research has confirmed the prominent role of group processes in the promotion and endorsement of disinformation. We report three studies on a psychological framework derived from integrated threat theory—a psychological theory which describes how perceived threat leads to group polarization and prejudice—composed of the following constructs: group belongingness, perceived threat, outgroup derogation, and intergroup anxiety. Our pilot study suggested that need to belong and intergroup anxiety predict antiscientific beliefs (pseudoscientific, paranormal, and conspiracy theories), thus justifying the general applicability of integrated threat theory. Study 1 investigates the transition from weak to strong critical thinking regarding pseudoscientific doctrines. Besides greater outgroup derogation and perceived threats among strong critical thinkers, the model does not perform well in this context. Study 2 focuses on the intergroup conflict around anthropogenic global warming, revealing the strong predictive power of the model. These results are discussed in relation to the distinctive psychological profiles of science acceptance and rejection

Hole-hole correlations in the U=∞U=\infty limit of the Hubbard model and the stability of the Nagaoka state

We use exact diagonalisation in order to study the infinite - $U$ limit of the two dimensional Hubbard model. As well as looking at single-particle correlations, such as $n_{{\bf k}\sigma }=\langle c^\dagger _{{\bf k}\sigma }c_{{\bf k}\sigma } \rangle$, we also study {\it N-particle correlation functions} which compare the relative positions of {\it all} the particles in different models. In particular we study 16 and 18-site clusters and compare the charge correlations in the Hubbard model with those of spinless fermions and hard-core bosons. We find that although low densities of holes favour a `locally-ferromagnetic' fermionic description, the correlations at larger densities resemble those of pure hard-core bosons surprisingly well .Comment: 15 pages, REVTE

Misinformation interventions decay rapidly without an immediate posttest

In recent years, many kinds of interventions have been developed that seek to reduce susceptibility to misinformation. In two preregistered longitudinal studies (N1 = 503, N2 = 673), we leverage two previously validated “inoculation” interventions (a video and a game) to address two important questions in misinformation interventions research: (1) whether displaying additional stimuli (such as videos unrelated to misinformation) alongside an intervention interferes with its effectiveness, and (2) whether administering an immediate posttest (in the form of a social media post evaluation task after the intervention) plays a role in the longevity of the intervention. We find no evidence that other stimuli interfere with intervention efficacy, but strong evidence that immediate posttests strengthen the learnings from the intervention. In study 1, we find that 48 h after watching a video, participants who received an immediate posttest continued to be significantly better at discerning untrustworthy social media posts from neutral ones than the control group (d = 0.416, p = .007), whereas participants who only received a posttest 48 h later showed no differences with a control (d = 0.010, p = .854). In study 2, we observe highly similar results for a gamified intervention, and provide evidence for a causal mechanism: immediate posttests help strengthen people's memory of the lessons learned in the intervention. We argue that the active rehearsal and application of relevant information are therefore requirements for the longevity of learning‐based misinformation interventions, which has substantial implications for their scalability

Quasiparticle Dispersion of the 2D Hubbard Model: From an Insulator to a Metal

On the basis of Quantum-Monte-Carlo results the evolution of the spectral weight $A(\vec k, \omega)$ of the two-dimensional Hubbard model is studied from insulating to metallic behavior. As observed in recent photoemission experiments for cuprates, the electronic excitations display essentially doping-independent features: a quasiparticle-like dispersive narrow band of width of the order of the exchange interaction $J$ and a broad valence- and conduction-band background. The continuous evolution is traced back to one and the same many-body origin: the doping-dependent antiferromagnetic spin-spin correlation.Comment: 11 pages, REVtex, 4 figures (in uuencoded postscript format

Dissociating Slow Responses From Slow Responding

Increased Intra-Subject Variability (ISV) is a candidate endophenotype of ADHD. ISV's relationship with response speed is highly relevant for ADHD as patients are highly variable but typically no slower than controls. This brief report addresses the relationship between variability and speed by employing dimensional analyses for differentiated performance measures, with a particular focus on the ex-Gaussian measures, across relevant ADHD studies and in young healthy adults (N = 70). For both patients with ADHD and healthy adults, we found that reaction time standard deviation and mean reaction time were strongly correlated, thus failing to dissociate, but ex-Gaussian tau (tau) shared only little variance with Gaussian mu (mu), thus dissociating slow responses (tau) from response speed or-if given-slow responding (mu). Our results highlight the utility of employing the ex-Gaussian measures to disentangle ISV and speed, particularly for ADHD data as patients make more slow responses but are not overall slower than typical controls

Cost-effectiveness of adding empagliflozin to the standard of care for patients with heart failure with reduced ejection fraction from the perspective of healthcare system in Malaysia

Objective: The aim of this study was to determine the cost-effectiveness of adding empagliflozin to the standard of care versus SoC alone for the treatment of patients with heart failure (HF) with reduced ejection fraction (HFrEF) from the perspective of the Ministry of Health of Malaysia.Methods: A cohort-based transition-state model, with health states defined as Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) quartiles and death, was used to determine the lifetime direct medical costs and quality-adjusted life years (QALYs) for both treatment groups. The risks of all-cause death, cardiovascular death, and health state utilities were estimated from the EMPEROR-Reduced trial. The incremental cost-effectiveness ratio (ICER) was assessed against the cost-effectiveness threshold (CET) as defined by the country’s gross domestic product per capita (RM 47,439 per QALY) to determine cost-effectiveness. Sensitivity analyses were conducted to assess the key model parameters’ uncertainty in respect to the incremental cost-effectiveness ratio. A scenario analysis was performed using health states as defined by the New York Heart Association classes.Results: Compared to SoC alone, empagliflozin + SoC for the treatment of HFrEF was more expensive (RM 25,333 vs. RM 21,675) but gained more health utilities (3.64 vs. 3.46), resulting in an ICER of RM 20,400 per QALY in the KCCQ-CSS model. A NYHA-based scenario analysis generated an ICER of RM 36,682 per QALY. A deterministic sensitivity analysis confirmed the robustness of the model in identifying the empagliflozin cost as the main driver of cost-effectiveness. The ICER was reduced to RM 6,621 when the government medication purchasing prices were used. A probabilistic sensitivity analysis with a CET of 1xGDP per capita reached 72.9% probability for empagliflozin + SoC against SoC being cost-effective.Conclusion: Empagliflozin + SoC compared to SoC alone for the treatment of HFrEF patients was cost-effective from the perspective of the MoH of Malaysia

Holstein polaron in two and three dimensions by quantum Monte Carlo

A recently developed quantum Monte Carlo approach to the Holstein model with one electron [PRB 69, 024301 (2004)] is extended to two and three dimensional lattices. A moderate sign problem occurs, which is found to diminish with increasing system size in all dimensions, and not to affect simulations significantly. We present an extensive study of the influence of temperature, system size, dimensionality and model parameters on the small-polaron cross over. Results are extrapolated to remove the error due to the Trotter discretization, which significantly improves the accuracy. Comparison with existing work and other quantum Monte Carlo methods is made. The method can be extended to the many-electron case.Comment: 14 pages, 11 figure

Realistic description of electron-energy loss spectroscopy for One-Dimensional Sr2_2CuO3_3

We investigate the electron-energy loss spectrum of one-dimensional undoped CuO$_{3}$ chains within an extended multi-band Hubbard model and an extended one-band Hubbard model, using the standard Lanczos algorithm. Short-range intersite Coulomb interactions are explicitly included in these models, and long-range interactions are treated in random-phase approximation. The results for the multi-band model with standard parameter values agree very well with experimental spectra of Sr$_{2}$CuO$_{3}$. In particular, the width of the main structure is correctly reproduced for all values of momentum transfer. It is shown for both models that intersite Coulomb interactions mainly lead to an energy shift of the spectra. We find no evidence for enhanced intersite interactions in Sr$_{2}$CuO$_{3}$.Comment: 4 pages, 4 figure