Pseudodoping of Metallic Two-Dimensional Materials by The Supporting Substrates

We demonstrate how hybridization between a two-dimensional material and its substrate can lead to an apparent heavy doping, using the example of monolayer TaS$_2$ grown on Au(111). Combining $\textit{ab-initio}$ calculations, scanning tunneling spectroscopy experiments and a generic model, we show that strong changes in Fermi areas can arise with much smaller actual charge transfer. This mechanism, which we refer to as pseudodoping, is a generic effect for metallic two-dimensional materials which are either adsorbed to metallic substrates or embedded in vertical heterostructures. It explains the apparent heavy doping of TaS$_2$ on Au(111) observed in photoemission spectroscopy and spectroscopic signatures in scanning tunneling spectroscopy. Pseudodoping is associated with non-linear energy-dependent shifts of electronic spectra, which our scanning tunneling spectroscopy experiments reveal for clean and defective TaS$_2$ monolayer on Au(111). The influence of pseudodoping on the formation of charge ordered, magnetic, or superconducting states is analyzed.Comment: arXiv admin note: substantial text overlap with arXiv:1609.0022

On Generators and Relations of the Rational Cohomology of Hilbert Schemes

We consider for $d\geq 1$ the graded commutative $\mathbb{Q}$-algebra $\mathcal{A}(d):=H^*(\operatorname{Hilb}^d(\mathbb{C}^2);\mathbb{Q})$, which is also connected to the study of generalised Hurwitz spaces by work of the first author. These Hurwitz spaces are in turn related to the moduli spaces of Riemann surfaces with boundary. We determine two distinct, minimal sets of $\lfloor d/2\rfloor$ multiplicative generators of $\mathcal{A}(d)$. Additionally, we prove when the lowest degree generating relations occur. For small values of $d$ we also determine a minimal set of generating relations, which leads to several conjectures about the necessary generating relations for $\mathcal{A}(d)$.Comment: 25 pages; v2. Minor revisions based on referee's comments. Published versio

The Spectrum of Yang Mills on a Sphere

In this note, we determine the representation content of the free, large N, SU(N) Yang Mills theory on a sphere by decomposing its thermal partition function into characters of the irreducible representations of the conformal group SO(4,2). We also discuss the generalization of this procedure to finding the representation content of N=4 Super Yang Mills.Comment: 18 pages v2. references added. typos fixe

Construcción y validación de dos escalas de adherencia a tratamientos de salud

47 p.El objetivo de la presente investigación consiste en construir y validar dos escalas de adherencia a tratamientos de salud en una muestra de 172 mujeres que ingresaban al sistema público de salud chileno para ser tratadas por depresión. Para ello se seleccionó 12 escalas fiables de adherencia desde las cuales se extrajeron y adaptaron los ítems, además de diseñar otros nuevos. Después de seleccionar los ítems más adecuados, se determinó su validez de constructo mediante un análisis factorial exploratorio (EFA). Los resultados de los EFA arrojan la existencia de 4 factores para la adherencia al tratamiento general y 1 para el tratamiento farmacológico. Luego, para confirmar esta estructura exploratoria, se realizó un análisis factorial confirmatorio (CFA). Como resultado, se obtiene un modelo de buen ajuste para la adherencia al tratamiento general (CMIN/DF=2.879; RMSEA=.108; NFI=.780; CFI=.843; TLI=.819; PNFI=.680; SMC=.590) y regular para el tratamiento farmacológico (CMIN/DF=3.084 RMSEA=.116; NFI=.925; CFI=.947; TLI=.932; PNFI=.719; SMC=.652). Además, se determina la confiabilidad de las escalas, donde ambas presentan indicadores excelentes (F=.901 y F=.949, respectivamente). Los resultados de esta investigación logran profundizar hallazgos anteriores (Nguyen et al. 2014) y enriquecer el concepto de adherencia, recabando información más precisa acerca de los distintos comportamientos, barreras y creencias asociadas a la adherencia. Finalmente, con el fin de facilitar la evaluación de la adherencia, se deja a disposición de los clínicos una versión de cada escala para ser aplicada e interpretada rápidamente.Palabras Clave: Adherencia al tratamiento, adherencia a medicación, validación de escala, análisis factorial

Band gap engineering by Bi intercalation of graphene on Ir(111)

We report on the structural and electronic properties of a single bismuth layer intercalated underneath a graphene layer grown on an Ir(111) single crystal. Scanning tunneling microscopy (STM) reveals a hexagonal surface structure and a dislocation network upon Bi intercalation, which we attribute to a $\sqrt{3}\times\sqrt{3}R30{\deg}$ Bi structure on the underlying Ir(111) surface. Ab-initio calculations show that this Bi structure is the most energetically favorable, and also illustrate that STM measurements are most sensitive to C atoms in close proximity to intercalated Bi atoms. Additionally, Bi intercalation induces a band gap ($E_g=0.42\,$eV) at the Dirac point of graphene and an overall n-doping ($\sim 0.39\,$eV), as seen in angular-resolved photoemission spectroscopy. We attribute the emergence of the band gap to the dislocation network which forms favorably along certain parts of the moir\'e structure induced by the graphene/Ir(111) interface.Comment: 5 figure

Crystalline and electronic structure of single-layer TaS2_2

Single-layer TaS$_2$ is epitaxially grown on Au(111) substrates. The resulting two-dimensional crystals adopt the 1H polymorph. The electronic structure is determined by angle-resolved photoemission spectroscopy and found to be in excellent agreement with density functional theory calculations. The single layer TaS$_2$ is found to be strongly n-doped, with a carrier concentration of 0.3(1) extra electrons per unit cell. No superconducting or charge density wave state is observed by scanning tunneling microscopy at temperatures down to 4.7 K.Comment: 6 pages, 4 figure

Chirality of tensor perturbations for complex values of the Immirzi parameter

In this paper we generalise previous work on tensor perturbations in a de Sitter background in terms of Ashtekar variables to cover all complex values of the Immirzi parameter gamma (previous work was restricted to imaginary gamma). Particular attention is paid to the case of real gamma. Following the same approach as in the imaginary case, we can obtain physical graviton states by invoking reality and torsion free conditions. The Hamiltonian in terms of graviton states has the same form whether gamma has a real part or not; however changes occur for the vacuum energy and fluctuations. Specifically, we observe a gamma dependent chiral asymmetry in the vacuum fluctuations only if gamma has an imaginary part. Ordering prescriptions also change this asymmetry. We thus present a measurable result for CMB polarisation experiments that could shed light on the workings of quantum gravity.Comment: 6 pages, 1 figur

Malignant melanoma associated with a blue naevus: a case report

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Absence of superconductivity in ultra-thin layers of FeSe synthesized on a topological insulator

The structural and electronic properties of FeSe ultra-thin layers on Bi$_{2}$Se$_{3}$ have been investigated with a combination of scanning tunneling microscopy and spectroscopy and angle-resolved photoemission spectroscopy. The FeSe multi-layers, which are predominantly 3-5 monolayers (ML) thick, exhibit a hole pocket-like electron band at \bar{\Gamma} and a dumbbell-like feature at \bar{M}, similar to multi-layers of FeSe on SrTiO$_{3}$. Moreover, the topological state of the Bi2Se3 is preserved beneath the FeSe layer, as indicated by a heavily \it{n}-doped Dirac cone. Low temperature STS does not exhibit a superconducting gap for any investigated thickness down to a temperature of 5 K