Disentanglement and Decoherence by Open System Dynamics

The destruction of quantum interference, decoherence, and the destruction of entanglement both appear to occur under the same circumstances. To address the connection between these two phenomena, we consider the evolution of arbitrary initial states of a two-particle system under open system dynamics described by a class of master equations which produce decoherence of each particle. We show that all initial states become separable after a finite time, and we produce the explicit form of the separated state. The result extends and amplifies an earlier result of Di\'osi. We illustrate the general result by considering the case in which the initial state is an EPR state (in which both the positions and momenta of a particle pair are perfectly correlated). This example clearly illustrates how the spreading out in phase space produced by the environment leads to certain disentanglement conditions becoming satisfied.Comment: 15 Page

THE EDUCATION JUSTICE: THE HONORABLE LEWIS FRANKLIN POWELL, JR.

The Honorable Lewis Franklin Powell, Jr. is “the education Justice” of the United States. During his tenure on the U.S. Supreme Court, from 1971 to 1987, Justice Powell authored at least twenty major opinions in education law, in addition to numerous significant concurrences and dissents. Just a sampling of Justice Powell\u27s majority opinions on education could form the bulk of an education law textbook recognizable by any American law student. This Article will explore some of Justice Powell\u27s major Supreme Court rulings in education law. It will also consider how these rulings may have related to aspects of Justice Powell\u27s life. In addition, the Article will briefly describe the Supreme Court\u27s current views on education and will attempt to describe how Justice Powell might analyze these issues today. At least one sitting Justice on the Supreme Court, Justice Sandra Day O\u27Connor, appears to have been influenced by Justice Powell\u27s views. Justice O\u27Connor occupies a similar ideological position on the Supreme Court as did Justice Powell, who wrote more than 250 majority opinions and whose “knack for being on the winning side never dropped below eighty per cent in any term, and often exceeded ninety per cent.

An overview of the Douglas Aircraft Company Aeroelastic Design Optimization Program (ADOP)

From a program manager's viewpoint, the history, scope and architecture of a major structural design program at Douglas Aircraft Company called Aeroelastic Design Optimization Program (ADOP) are described. ADOP was originally intended for the rapid, accurate, cost-effective evaluation of relatively small structural models at the advanced design level, resulting in improved proposal competitiveness and avoiding many costly changes later in the design cycle. Before release of the initial version in November 1987, however, the program was expanded to handle very large production-type analyses

Regulating autonomous agents facing conflicting objectives : a command and control example

UK military commanders have a degree of devolved decision authority delegated from command and control (C2) regulators, and they are trained and expected to act rationally and accountably. Therefore from a Bayesian perspective they should be subjective expected utility maximizers. In fact they largely appear to be so. However when current tactical objectives conflict with broader campaign objective there is a strong risk that fielded commanders will lose rationality and coherence. By systematically analysing the geometry of their expected utilities, arising from a utility function with two attributes, we demonstrate in this paper that even when a remote C2 regulator can predict only the likely broad shape of her agents' marginal utility functions it is still often possible for her to identify robustly those settings where the commander is at risk of making inappropriate decisions

\u27Dear Colleague\u27 letter

\u27Dear Colleague\u27 letter for the September 2006 briefing on Children\u27s Well-Being and the Role of Workplace Flexibility for Parents event. Prepared on behalf of Workplace Flexibility 2010 by Senator Mike DeWine and Senator Christopher J. Dodd

Influence of water absorption in flexible epoxy resins on the space charge behaviour

The aim of the current work is to achieve a better understanding of the influence of water uptake in flexible epoxy resins on the space charge dynamics at high electric fields. The space charge behaviour was studied using pulsed electroacoustic (PEA) technique. The samples were prepared from Araldite CY1311, which is a bisphenol-A epoxy resin. This particular resin was chosen because its glass transition is 0°C and hence it is in a flexible state at room temperature. All samples were conditioned in containers with saturated salt solutions or de-ionised water so that various water uptake levels were obtained. It was found that the space charge dynamics was correlated with the amount of absorbed water in the samples and this is consistent with the dielectric measurements made on the same material where ion transport was identified as the main charge transport process from the observed QDC behaviour

Limitations of Kramers-Kronig transform for calculation of the DC conductance magnitude from dielectric measurements

The Kramers-Kronig (K-K) transform relates the real and imaginary parts of the complex susceptibility as a consequence of the principle of causality. It is a special case of the Hilbert transform and it is often used for estimation of the DC conductance from dielectric measurements. In this work, the practical limitations of a numerical implementation of the Kramers-Kronig transform was investigated in the case of materials that exhibit both DC conductance and quasi-DC (QDC) charge transport processes such as epoxy resins. The characteristic feature of a QDC process is that the real and imaginary parts of susceptibility (permittivity) follow fractional power law dependences with frequency with the low frequency exponent approaching -1. Dipolar relaxation in solids on the other hand has a lower frequency exponent <1. The computational procedure proposed by Jonscher for calculation of the K-K transform involves extrapolation and truncation of the data to low frequencies so that convergence of the integrals is ensured. The validity of the analysis is demonstrated by performing K-K transformation on real experimental data and on theoretical data generated using the Dissado-Hill function. It has been found that the algorithm works well for dielectric relaxation responses but it is apparent that it does not work in the case of a low frequency power law in which the low frequency exponent approaches -1, i.e. in the case of QDC responses. In this case convergence can only be guaranteed by extrapolating the low frequency power law over many decades towards zero frequency

Mössbauer Spectrometry Study of Thermally-Activated Electronic Processes in Li_xFePO_4

The solid solution phase of Li_xFePO_4 with different Li concentrations, x, was investigated by Mössbauer spectrometry at temperatures between 25 and 210 °C. The Mössbauer spectra show a temperature dependence of their isomer shifts (E_(IS)) and electric quadrupole splittings (E_Q), typical of thermally activated, electronic relaxation processes involving ^(57)Fe ions. The activation energies for the fluctuations of E_Q and E_(IS) for Fe^(3+) are nearly the same, 570 ± 9 meV, suggesting that both originate from charge hopping. For the Fe^(2+) components of the spectra, the fluctuations of E_Q occurred at lower temperatures than the fluctuations of E_(IS), with an activation energy of 512 ± 12 meV for E_Q and one of 551 ± 7 meV for E_(IS). The more facile fluctuations of E_Q for Fe^(2+) are evidence for local motions of neighboring Li^+ ions. It appears that the electron hopping frequency is lower than that of Li^+ ions. The activation energies of relaxation did not have a measurable dependence on the concentration of lithium, x