Chaotic Electron Motion in Superlattices. Quantum-Classical Correspondence of the Structure of Eigenstates and LDOS

We investigate the classical-quantum correspondence for particle motion in a superlattice in the form of a 2D channel with periodic modulated boundaries. Its classical dynamics undergoes the generic transition to chaos of Hamiltonian systems as the amplitude of the modulation is increased. We show that for strong chaotic motion, the classical counterpart of the structure of eigenstates (SES) in energy space reveals an excellent agreement with the quantum one. This correspondence allows us to understand important features of the SES in terms of classical trajectories. We also show that for typical 2D modulated waveguides there exist, at any energy range, extremely localized eigenstates (in energy) which are practically unperturbed by the modulation. These states contribute to the strong fluctuations around the classical SES. The approach to the classical limit is discussed.Comment: 4 pages, 4 figure

Sleeping Beauty: Exploring a Neglected Solution

The strong law of large numbers and considerations concerning additional information strongly suggest that Beauty upon awakening has probability 1/3 to be in a heads-awakening but should still believe the probability that the coin landed heads in the Sunday toss to be 1/2. The problem is that she is in a heads-awakening if and only if the coin landed heads. So, how can she rationally assign different probabilities or credences to propositions she knows imply each other? This is the problem I address in this article. I suggest that ‘p whenever q and vice versa’ may be consistent with p and q having different probabilities if one of them refers to a sample space containing ordinary possible worlds and the other to a sample space containing centred possible worlds, because such spaces may fail to combine into one composite probability space and, as a consequence, ‘whenever’ may not be well defined; such is the main contribution of this article. 1The Sleeping Beauty Game2Groisman’s and Peter Lewis’s Approaches3Discussing Beauty’s Credences4The Principle of Equivalence's Failure5Making Sense of the Principle of Equivalence's Failure6Elga’s and Lewis’s Approaches7ConclusionAppendi

Race, Crime, and Institutional Design

Minorities are gravely overrepresented in every stage of the criminal process--from pedestrian and automobile stops, to searches and seizures, to arrests and convictions, to incarceration and capital punishment. While racial data can provide a snapshot of the current state of affairs, such information rarely satisfies questions of causation, and usually only sets the scene for normative theory

Caracterización de una empresa de servicios energéticos. Caso práctico: comercio

Este documento trata en primera instancia de describir la problemática existente en materia de energía a nivel global situándola en un contexto socio-cultural. Este proyecto abarca el concepto de la importancia de la eficiencia energética definiéndola desde el punto de vista conceptual, evaluando su impacto en el consumo energético, así como la implantación de la Normativa ISO 50001. Posteriormente se describe un plan de negocio de servicios energéticos destinados al sector comercial principalmente, donde se establece los criterios para el desarrollo de la actividad empresarial en el sector energético. Describimos los servicios energéticos que prestaría la empresa de servicios energéticos al sector comercial. Por último se detalla la metodología para una Auditoría Energética en un comercio, se estima los ahorros a nivel energético y económico para posteriormente ejecutar un plan de acción y plantear unas recomendaciones para la mejora de la eficiencia energética del local

Two-plane balance and slip-ring design

A 3.25 cm (1.28 in.) two plane balance and eight channel slip ring assembly has been designed to measure and transmit the thrust (667-N;150-lb) and torque (135-N-m;100-lb-ft) components produced by wind tunnel model turboprops and drive motors operating at 300 Hz