Chirality Probe of Twisted Bilayer Graphene in the Linear Transport Regime.

We propose minimal transport experiments in the coherent regime that can probe the chirality of twisted moiré structures. We show that only with a third contact and in the presence of an in-plane magnetic field (or another time-reversal symmetry breaking effect) a chiral system may display nonreciprocal transport in the linear regime. We then propose to use the third lead as a voltage probe and show that opposite enantiomers give rise to different voltage drops on the third lead.

Caries indicators in relation to healthcare access and hygienic-dietary habits in Spanish preschoolers.

Introduction: Dental caries continues to be a public healthcare problem due to its high prevalence and morbidity. It was proposed to evaluate caries indicators in relation to healthcare access and hygienic-dietary habits in Spanish preschoolers.

Materials And Methods: A cross-sectional study was carried out on a random sample consisting of 343 patients ranging from 3 to 5 years of age in the primary care setting, the main measurements were: dental care access, hygienic-dietary habits, and caries registration according to WHO criteria.

Relevance of Sociocultural Inequalities and Parents' Origins in Relation to the Oral Health of Preschoolers in Lanzarote, Spain.

Approaching inequalities to achieve health equity requires joint action. Early childhood caries affects disadvantaged population groups. The objective of this study was to determine the relevance of sociocultural inequalities and parental origin with respect to oral health in preschool children in Lanzarote.

Prevalence of traumatic injuries in deciduous dentition and associated risk factors in a Spanish children population.

Background: The frequency of traumatic dental injuries (TDI) in primary dentition and those agents that favor them present a great variability. Therefore, the objective of this study was to determine the prevalence of TDI in a population of Spanish preschoolers in temporary dentition and identify the factors associated with these injuries.

Material And Methods: An epidemiological observational prevalence study was carried out.

Plasmon-Enhanced Near-Field Chirality in Twisted van der Waals Heterostructures.

It is shown that chiral plasmons, characterized by a longitudinal magnetic moment accompanying the longitudinal charge plasmon, lead to electromagnetic near-fields that are also chiral. For twisted bilayer graphene, we estimate that the near-field chirality of screened plasmons can be several orders of magnitude larger than that of the related circularly polarized light. The chirality also manifests itself in a deflection angle that is formed between the direction of the plasmon propagation and its Poynting vector.

Chiral Plasmons with Twisted Atomic Bilayers.

van der Waals heterostructures of atomically thin layers with rotational misalignments, such as twisted bilayer graphene, feature interesting structural moiré superlattices. Because of the quantum coupling between the twisted atomic layers, light-matter interaction is inherently chiral; as such, they provide a promising platform for chiral plasmons in the extreme nanoscale. However, while the interlayer quantum coupling can be significant, its influence on chiral plasmons still remains elusive.

Emergent magnetic texture in driven twisted bilayer graphene.

The transport properties of a twisted bilayer graphene barrier are investigated for various twist angles. Remarkably, for small twist angles around the magic angle θm ∼ 1.05°, the local currents around the AA-stacked regions are strongly enhanced compared to the injected electron rate.

Nonlocal Quantum Effects in Plasmons of Graphene Superlattices.

By using a nonlocal, quantum mechanical response function we study graphene plasmons in a one-dimensional superlattice (SL) potential V_{0}cosG_{0}x. The SL introduces a quantum energy scale E_{G}∼ℏv_{F}G_{0} associated with electronic subband transitions. At energies lower than E_{G}, the plasmon dispersion is highly anisotropic; plasmons propagate perpendicularly to the SL axis, but become damped by electronic transitions along the SL direction.

Chiral Response of Twisted Bilayer Graphene.

We present an effective (minimal) theory for chiral two-dimensional materials. These materials possess an electromagnetic coupling without exhibiting a topological gap. As an example, we study the response of doped twisted bilayers, unveiling unusual phenomena in the zero frequency limit.

Extraordinary absorption of decorated undoped graphene.

We theoretically study absorption by an undoped graphene layer decorated with arrays of small particles. We discuss periodic and random arrays within a common formalism, which predicts a maximum absorption of 50% for suspended graphene in both cases. The limits of weak and strong scatterers are investigated, and an unusual dependence on particle-graphene separation is found and explained in terms of the effective number of contributing evanescent diffraction orders of the array.

Measurable lattice effects on the charge and magnetic response in graphene.

The simplest tight-binding model is used to study lattice effects on two properties of doped graphene: (i) magnetic orbital susceptibility and (ii) regular Friedel oscillations, both suppressed in the usual Dirac cone approximation. (i) An exact expression for the tight-binding magnetic susceptibility is obtained, leading to orbital paramagnetism in graphene for a wide range of doping levels which is relevant when compared with other contributions. (ii) Friedel oscillations in the coarse-grained charge response are considered numerically and analytically and an explicit expression for the response to lowest order in lattice effects is presented, showing the restoration of regular 2d behavior, but with strong sixfold anisotropy.

Healthy mind and body in a healthy work environment.

Objectives: To assess the relationship between psychological distress and physical somatic symptoms as well as work environment conditions in the diverse population of dentists based in the Canary Islands (Spain).

Methods: 203 dentists officially registered with the local General Dental Councils, returned the questionnaire delivered by mail. Participants provided information on demographic characteristics, self-constructed questions like self-perceived environmental working conditions (location, access, temperature, humidity and pollution).

Evolution of caries and fluorosis in schoolchildren of the Canary Islands (Spain): 1991, 1998, 2006.

The aim of this work is to assess the evolution of caries and fluorosis prevalence and indices at 7 and 12 years of age in the Canary Islands through three cross epidemiological studies conducted in 1991, 1998 and 2006. The three studies followed a similar methodology, using the WHO diagnosis criteria and indications, except for the assessment of fluorosis, which was measured with the "Thylstrup and Fejerskov" index. The examining dentists were trained and calibrated in an area with high endemic fluorosis.

Tunneling mechanism of light transmission through metallic films.

A mechanism of light transmission through metallic films is proposed, assisted by tunneling between resonating buried dielectric inclusions. This is illustrated by arrays of Si spheres embedded in Ag. Strong transmission peaks are observed near the Mie resonances of the spheres.

Universal features of the time evolution of evanescent modes in a left-handed perfect lens.

The time evolution of evanescent modes in Pendry's perfect lens proposal for ideally lossless and homogeneous, left-handed materials is analyzed. We show that time development of subwavelength resolution exhibits universal features, independent of model details. This is due to the unavoidable near degeneracy of surface electromagnetic modes in the deep subwavelength region.