Autoresonant control of the many-electron dynamics in nonparabolic quantum wells

The optical response of nonparabolic quantum wells is dominated by a strong peak at the plasmon frequency. When the electrons reach the anharmonic regions, resonant absorption becomes inefficient. This limitation is overcome by using a chirped laser pulse in the autoresonant regime. By direct simulations using the Wigner phase-space approach, the authors prove that, with a sequence of just a few pulses, electrons can be efficiently detrapped from a nonparabolic well. For an array of multiple quantum wells, they can create and control an electronic current by suitably applying an autoresonant laser pulse and a slowly varying dc electric field.Comment: 3 page

Weibel Instabilities in Dense Quantum Plasmas

The quantum effect on the Weibel instability in an unmagnetized plasma is presented. Our analysis shows that the quantum effect tends to stabilize the Weibel instability in the hydrodynamic regime, whereas it produces a new oscillatory instability in the kinetic regime. A novel effect the quantum damping, which is associated with the Landau damping, is disclosed. The new quantum Weibel instability may be responsible for the generation of non-stationary magnetic fields in compact astrophysical objects as well as in the forthcoming intense laser-solid density plasma experiments.Comment: Submitted to PR

Theory and applications of the Vlasov equation

Forty articles have been recently published in EPJD as contributions to the topical issue "Theory and applications of the Vlasov equation". The aim of this topical issue was to provide a forum for the presentation of a broad variety of scientific results involving the Vlasov equation. In this editorial, after some introductory notes, a brief account is given of the main points addressed in these papers and of the perspectives they open.Comment: Editoria

Uncertainty quantification of cable inductances and capacitances via mixed-fidelity models

In this paper, we investigate a mixed-fidelity approach for the uncertainty quantification of the per-unit-length (p.u.l.) capacitance and inductance of cables with random geometrical and material parameters. Polynomial chaos expansion is used to model uncertainty, whereas a numerical discretization technique is used to calculate p.u.l. inductances and capacitances. However, instead of using a model with high fidelity in both features, the results are obtained as a combination of two complementary models with mixed fidelity in each feature. Numerical examples concerning the statistical assessment of the p.u.l. inductance and capacitance matrices of two shielded cables show that similar accuracy is attained at a fraction of the computational cost compared to conventional approaches

Comparison of Stochastic Methods for the Variability Assessment of Technology Parameters

This paper provides and compares two alternative solutions for the simulation of cables and interconnects with the inclusion of the effects of parameter uncertainties, namely the Polynomial Chaos (PC) method and the Response Surface Modeling (RSM). The problem formulation applies to the telegraphers equations with stochastic coefficients. According to PC, the solution requires an expansion of the unknown parameters in terms of orthogonal polynomials of random variables. On the contrary, RSM is based on a least-square polynomial fitting of the system response. The proposed methods offer accuracy and improved efficiency in computing the parameter variability effects on system responses with respect to the conventional Monte Carlo approach. These approaches are validated by means of the application to the stochastic analysis of a commercial multiconductor flat cable. This analysis allows us to highlight the respective advantages and disadvantages of the presented method

Energy Level Quasi-Crossings: Accidental Degeneracies or Signature of Quantum Chaos?

In the field of quantum chaos, the study of energy levels plays an important role. The aim of this review paper is to critically discuss some of the main contributions regarding the connection between classical dynamics, semi-classical quantization and spectral statistics of energy levels. In particular, we analyze in detail degeneracies and quasi-crossings in the eigenvalues of quantum Hamiltonians which are classically non-integrable. Summary: 1. Introduction; 2. Quasi-Crossing and Chaos; 3. Molecular Spectroscopy; 4. Nuclear Models; 4.1 Zirnbauer-Verbaashot-Weidenmuller Model; 4.2 Lipkin-Meshow-Glick Model; 5. Particle Physics and Field Theory; 6. Conclusions.Comment: 26 pages, Latex, 9 figures, to be published in International Journal of Modern Physics

Conservatives, the Supreme Court, and the Constitution: Judicial-Government Relations, 2006-15

Three high profile government losses in the Supreme Court in late 2013 and early 2014, combined with the government’s response to those losses, generated a narrative of an especially fractious relationship between the Conservative government of Prime Minister Stephen Harper and the Court. This article analyzes this narrative more rigorously by going beyond a mere tallying of government wins and losses in the Court. Specifically, it examines Charter-based invalidations of federal legislation since 2006, three critical reference opinions rendered at the government’s own request, and two key judgments delivered in the spring of 2015 concerning aboriginal rights and the elimination of the long-gun registry. The article argues that the relationship between the Conservative government and the Court from 2006 to 2015 was much more complicated than the “fractious relationship” narrative would suggest. However, the Conservative government did adopt a more consistently confrontational approach in its legislative responses than its predecessors