Multi-vortex dynamics in junctions of charge density waves

Ground state reconstruction by creation of topological defects in junctions of CDWs is a convenient playground for modern efforts of field-effect transformations in strongly correlated materials with spontaneous symmetry breakings. Being transient, this effect contributes also to another new science of pump-induced phase transitions. We present a dynamical model for behavior of the CDW in restricted geometries of junctions under an applied voltage or a passing current. The model takes into account multiple interacting fields: the amplitude and the phase of the CDW complex order parameter, distributions of the electric field, the density and the current of various normal carriers. A particular challenge was to monitor the local conservation of the condensed and the normal charge densities. That was done easily invoking the chiral invariance and the associated anomaly, but prize is an unconventional Ginsburg-Landau type theory which is not analytic with respect to the order parameter. The numerical modeling poses unusual difficulties but still can demonstrate that vortices are nucleated at the junction boundary when the voltage across, or the current through, exceed a threshold.Comment: To be published in proceedings of the conference SUPERSTRIPES-2014, A. Bianconi ed., J. Supercond. Nov. Mag., (2015

A Latin American perspective on diversity management: what does "inclusion" mean in a Peruvian context?

Although interest in inclusion is becoming widespread, there remains limited understanding of how organizations can create environments that promote inclusiveness and unlock the benefits of workforce diversity. Additional research is needed to better understand how inclusion is conceptualized and experienced in contexts other than North America and Europe. Taking an exploratory approach, the present research seeks to answer the question of how employees in Peru – one of the most socially and economically unequal nations in Latin America - understand the concept of inclusion in the workplace. Semi-structured interviews with thirty employed individuals found that inclusion was generally described as comprising belongingness, uniqueness, and equal treatment. Six elements emerged as key to the creation of workplace inclusion: participation, positive relationships, equality, feeling valued, climate and culture, and positive work conditions. As inhabitants of a developing country with high levels of inequality and discrimination, Peruvian employees’ views provide valuable insight into how inclusion is lived and understood in such a context, and how it may be augmented

Theory and experiment of the ESR of Co2+^{2+} in Zn2_2 % (OH)PO4_4 and Mg2_2(OH)AsO4_4

Experiments of Electron Spin Resonance (ESR) were performed on Co$$ substituting Zn$^{2+}$ or Mg$^{2+}$ in powder samples of Zn$_2$(OH)PO$_4$ and Mg$_2$(OH)AsO$_4$. The observed resonances are described with a theoretical model that considers the departures from the two perfect structures. It is shown that the resonance in the penta-coordinated complex is allowed, and the crystal fields that would describe the resonance of the Co$^{2+}$ in the two environments are calculated. The small intensity of the resonance in the penta-coordinated complex is explained assuming that this site is much less populated than the octahedral one; this assumption was verified by a molecular calculation of the energies of the two environments, with both Co and Zn as central ions in Zn$_2$(OH)PO$_4$.Comment: 43 pages, LaTex file, 6 figures, EPS. submitted to Journal of Physics Condens

A Tonks Giradeau Gas in the Presence of a Local Potential

The physics of a Tonks-Giradeau Gas in the presence of a local potential is studied. In order to evaluate the single particle density matrix (SPDM) of the many-body ground state, the Wiger-Jordan transformation is used. The eigenvector with the largest eigenvalue of the SPDM corresponds to the "Bose-Einstein Condensate"(BEC) State. We find that the "BEC" state density at the positon of the local potential decreases, as expected, in the case of a repulsive potential. For an attractive potential, it decreases or increases depending on the strength of the potential. The superfluidity of this system is investigated both numerically and perturbatively. An experimental method for detecting the effect of an impurity in a Tonks-Giradueau gas is discussed.Comment: 14 pages, 5 figure

Tunneling edges at strong disorder

Scattering between edge states that bound one-dimensional domains of opposite potential or flux is studied, in the presence of strong potential or flux disorder. A mobility edge is found as a function of disorder and energy, and we have characterized the extended phase. "paper_FINAL.tex" 439 lines, 20366 characters In the presence of flux and/or potential disorder, the localization length scales exponentially with the width of the barrier. We discuss implications for the random-flux problem.Comment: RevTeX, 4 page

New constraints on the formation and settling of dust in the atmospheres of young M and L dwarfs

We obtained medium-resolution near-infrared spectra of seven young M9.5-L3 dwarfs classified in the optical. We aim to confirm the low surface gravity of the objects in the NIR. We also test whether atmospheric models correctly represent the formation and the settling of dust clouds in the atmosphere of young late-M and L dwarfs. We used ISAAC at VLT to obtain the spectra of the targets. We compared them to those of mature and young BD, and young late-type companions to nearby stars with known ages, in order to identify and study gravity-sensitive features. We computed spectral indices weakly sensitive to the surface gravity to derive near-infrared spectral types. Finally, we found the best fit between each spectrum and synthetic spectra from the BT-Settl 2010 and 2013 models. Using the best fit, we derived the atmospheric parameters of the objects and identify which spectral characteristics the models do not reproduce. We confirmed that our objects are young BD and we found NIR spectral types in agreement with the ones determined at optical wavelengths. The spectrum of the L2-gamma dwarf 2MASSJ2322-6151 reproduces well the spectrum of the planetary mass companion 1RXS J1609-2105b. BT-Settl models fit the spectra and the 1-5 $\mu$m SED of the L0-L3 dwarfs for temperatures between 1600-2000 K. But the models fail to reproduce the shape of the H band, and the NIR slope of some of our targets. This fact, and the best fit solutions found with super-solar metallicity are indicative of a lack of dust, in particular at high altitude, in the cloud models. The modeling of the vertical mixing and of the grain growth will be revised in the next version of the BT-Settl models. These revisions may suppress the remaining non-reproducibilities.Comment: Accepted in A&A, February 6, 201

Compact, low power and low threshold electrically pumped micro disc lasers for 20Gb/s non return to zero all optical wavelength conversion

\u3cp\u3eUsing a 7.5μm wide InP Micro-Disc-Laser, with a very low ∼100μA threshold current, heterogeneously integrated on top of Silicon on Insulator substrate, all optical NRZ wavelength conversion at speeds up to 20Gb/s is demonstrated.\u3c/p\u3

Civic Education and Democratic Backsliding in the Wake of Kenya’s Post-2007 Election Violence

This article examines two unexplored questions concerning the impact of civic education programs in emerging democracies: (1) whether such programs have longer-terms effects and (2) whether civic education can be effective under conditions of democratic “backsliding.” We investigate these questions in the context of a large-scale civic education program in Kenya just before the disputed 2007 election that sparked a wave of ethnic clashes and brought the country to the brink of civil war. Analysis of a survey of 1,800 “treatment” and 1,800 “control” individuals shows that the program had significant long-term effects on variables related to civic competence and engagement, with less consistent effects on democratic values. We also find that participants who subsequently were affected by the violence were less likely to adopt negative beliefs about Kenya’s political system, less likely to support the use of ethnic or political violence, and more likely to forgive those responsible for the post-election violence

Uncertainty assessment for measurement processes in the aerospace manufacturing industry

Measurement processes are critical to the aerospace industry, which products must follow strict regulations and customer requirements. Additionally, measurement of uncertainty is fast becoming a requirement from both certification bodies and customers. An uncertainty assessment must be carried out for all processes that need to add an uncertainty statement to the measurement result. In order to maintain defined quality standards, aerospace manufacturing companies need to identify all measurement disciplines that benefit from stating the level of uncertainty and define a methodology to calculate it for complex measurement processes. An extensive research has been conducted in order to define the most appropriate methodology to assess uncertainty on complex aerospace components and a case study has been applied to assess the strain gauge calibration test uncertainty of different aerospace components. This study develops a generic framework, which helps the assessment of all individual sources of uncertainty and completes the one established by the Guide to the Expression of Uncertainty in Measurement. Conclusions have been extracted from the outcome of the case study. The conducted research contributes to a better understanding of measurement processes and good practices that lead to lower uncertainty. The outcome will help manufacturing companies to be aware of the contributors of uncertainty to the tests, how to reduce this uncertainty and the reliability of the measurements taken during the process