Solution to the Landau-Zener problem via Susskind-Glogower operators

We show that, by means of a right-unitary transformation, the fully quantized Landau-Zener Hamiltonian in the weak-coupling regime may be solved by using known solutions from the standard Landau-Zener problem. In the strong-coupling regime, where the rotating wave approximation is not valid, we show that the quantized Landau-Zener Hamiltonian may be diagonalized in the atomic basis by means of a unitary transformation; hence allowing numerical solutions for the few photons regime via truncation.Comment: 6 pages, 5 figure

The effect of international trade on mark-ups distribution

This paper presents empirical evidence about the relationship between market openness and markup distribution of manufacturing firms. The empirical analysis uses a panel data set of Spanish firms in the period 1990-2005, with a structural approach that lets us to identify individual mark-ups. The results point out that tougher competition associated to openness reduces the average of marginal costs and prices, while it increases the average firm size. However, the evidence about the effect on average markups and the dispersion of performance variables is weaker. These results partially support the theoretical predictions by the recent literature on efficiency heterogeneity and international trade and, in particular, Melitz and Ottaviano (2008).markups, marginal costs, size, openness

Markups, bargaining power and offshoring: an empirical assessment

This paper tests the pro-competitive effect of imports on product and labour markets for Spanish manufacturing firms in the period 1990-2005. In doing so, it takes into account the type of imported products: final vs intermediate. Markups are estimated following the procedure suggested by Roeger (1995) and including an efficient bargaining model. The observed heterogeneity among firms is parameterized to consider additional product standardization and market concentration. The results support the Imports as Market Discipline hypothesis for importers of final goods, while firms that offshore intermediate inputs show similar markups to non-importers. Additionally, the union bargaining power is smaller the more final-goods oriented imports are and the more homogeneous is the type of goods elaborated by firms.Markups, offshoring, bargaining power

Socioeconomic effects of protected areas in Spain across spatial scales and protection levels

Impacts of the legal designation of protected areas (PAs) may have contrasting implications for different stakeholders, and at different spatial scales. In this study, we analysed the organisational perception on the socioeconomic effects of PA designation from all sectors of activity in Spain, accounting for PAs’ legal stringency. A semi-structured questionnaire was administered to 68 organisations at national, regional (Andalusia) and local scales (two municipalities in the Almeria province, Andalusia) through an online survey. Local stakeholders and the primary, secondary and tertiary sectors were most concerned about the social and economic impacts of PAs designation on their organisations. By contrast, organisations at the national or regional scales together with public institutions, the quaternary sector and other miscellaneous stakeholders perceived predominantly positive effects. Only national organisations perceived an increase in local social and economic effects from the designation of legally stringent PAs with regard to multiple-use PAs

Self-similar transmission properties of aperiodic Cantor potentials in gapped graphene

We investigate the transmission properties of quasiperiodic or aperiodic structures based on graphene arranged according to the Cantor sequence. In particular, we have found self-similar behaviour in the transmission spectra, and most importantly, we have calculated the scalability of the spectra. To do this, we implement and propose scaling rules for each one of the fundamental parameters: generation number, height of the barriers and length of the system. With this in mind we have been able to reproduce the reference transmission spectrum, applying the appropriate scaling rule, by means of the scaled transmission spectrum. These scaling rules are valid for both normal and oblique incidence, and as far as we can see the basic ingredients to obtain self-similar characteristics are: relativistic Dirac electrons, a self-similar structure and the non-conservation of the pseudo-spin. This constitutes a reduction of the number of conditions needed to observe self-similarity in graphene-based structures, see D\'iaz-Guerrero et al. [D. S. D\'iaz-Guerrero, L. M. Gaggero-Sager, I. Rodr\'iguez-Vargas, and G. G. Naumis, arXiv:1503.03412v1, 2015]