Temperature dependence of the average electron-hole pair creation energy in Al0.8Ga0.2As

The temperature dependence of the average energy consumed in the creation of an electron-hole pair in the wide bandgap compound semiconductor Al 0.8Ga0.2As is reported following X-ray measurements made using an Al0.8Ga0.2As photodiode diode coupled to a low-noise charge-sensitive preamplifier operating in spectroscopic photon counting mode. The temperature dependence is reported over the range of 261 K-342 K and is found to be best represented by the equation ε AlGaAs 7.327-0.0077 T, where εAlGaAs is the average electron-hole pair creation energy in eV and T is the temperature in K. © 2013 © 2013 Author(s)

Retrodiction as a tool for micromaser field measurements

We use retrodictive quantum theory to describe cavity field measurements by successive atomic detections in the micromaser. We calculate the state of the micromaser cavity field prior to detection of sequences of atoms in either the excited or ground state, for atoms that are initially prepared in the excited state. This provides the POM elements, which describe such sequences of measurements.Comment: 20 pages, 4(8) figure

Flexible Invariants Through Semantic Collaboration

Modular reasoning about class invariants is challenging in the presence of dependencies among collaborating objects that need to maintain global consistency. This paper presents semantic collaboration: a novel methodology to specify and reason about class invariants of sequential object-oriented programs, which models dependencies between collaborating objects by semantic means. Combined with a simple ownership mechanism and useful default schemes, semantic collaboration achieves the flexibility necessary to reason about complicated inter-object dependencies but requires limited annotation burden when applied to standard specification patterns. The methodology is implemented in AutoProof, our program verifier for the Eiffel programming language (but it is applicable to any language supporting some form of representation invariants). An evaluation on several challenge problems proposed in the literature demonstrates that it can handle a variety of idiomatic collaboration patterns, and is more widely applicable than the existing invariant methodologies.Comment: 22 page

Atmospheric transmission computer program CP

A computer program is described which allows for calculation of the effects of carbon dioxide, water vapor, methane, ozone, carbon monoxide, and nitrous oxide on earth resources remote sensing techniques. A flow chart of the program and operating instructions are provided. Comparisons are made between the atmospheric transmission obtained from laboratory and spacecraft spectrometer data and that obtained from a computer prediction using a model atmosphere and radiosonde data. Limitations of the model atmosphere are discussed. The computer program listings, input card formats, and sample runs for both radiosonde data and laboratory data are included

The Privileges or Immunities Clause, Abridged: A Critique of Kurt Lash on the Fourteenth Amendment

In earlier writings, both of us have expressed sympathy for the view that the Privileges or Immunities Clause affords absolute protection to unenumerated rights, such as those contained in the Civil Rights Act of 1866, and authorizes Congress to enact protective legislation. Neither of us, however, has engaged with Kurt Lash’s most recent and unique two-class interpretation of the original meaning of the Privileges or Immunities Clause in the depth that it deserves. Nor have we evaluated his recent efforts to demonstrate that the Fourteenth Amendment’s Due Process of Law Clause empowers the federal courts and Congress to protect unenumerated rights like the right to make contracts, among others listed in the Civil Rights Act of 1866. In this Article, we will do so. We will contend that Lash has provided readers with an abridged version of the Privileges or Immunities Clause. In future writing, we will advance a competing account of the original public meaning of the Privileges or Immunities Clause. We will also develop a framework that can be used by judges and legislators to identify the rights protected by the Clause, to thwart state abridgments of those rights, and to evaluate congressional legislation that is purportedly designed to protect those rights. Part I provides an exposition of Lash’s thesis. Because his arguments are complex, and rely on diverse evidence, our summary is lengthy. Given the multiplicity of his publications on the subject, we think an accurate summary of Lash’s approach is both independently worthwhile and a necessary prelude to any critique. Part II systematically critiques Lash’s evidence and arguments. We find that Lash’s enumerated-rights-only—or “ERO”—theory has little support in antebellum jurisprudence; that the evidence Lash offers to show that John Bingham, upon whose testimony Lash heavily relies, held Lash’s ERO theory is equivocal at best; and that Lash’s ERO theory was not widely shared by the Fourteenth Amendment’s framers. We then explain why evidence from the debate over ratification does not indicate that the ERO theory was embraced by the public. Next, we canvass postratification jurisprudence and congressional debates over various pieces of civil rights legislation both prior to and shortly after the Supreme Court’s fateful decisions in the Slaughter-House Cases and United States v. Cruikshank—decisions that are generally regarded as having rendered the Privileges or Immunities a “practical nullity.” We find that the interpretations of the Clause that are contained in these materials are, for the most part, inconsistent with Lash’s ERO theory. Finally, we engage and respond to Lash’s argument that the political dynamics during the relevant time period made it impossible for any constitutional amendment that delegated to Congress and the federal courts the power to enforce unenumerated rights to be ratified

Large-uncertainty intelligent states for angular momentum and angle

The equality in the uncertainty principle for linear momentum and position is obtained for states which also minimize the uncertainty product. However, in the uncertainty relation for angular momentum and angular position both sides of the inequality are state dependent and therefore the intelligent states, which satisfy the equality, do not necessarily give a minimum for the uncertainty product. In this paper, we highlight the difference between intelligent states and minimum uncertainty states by investigating a class of intelligent states which obey the equality in the angular uncertainty relation while having an arbitrarily large uncertainty product. To develop an understanding for the uncertainties of angle and angular momentum for the large-uncertainty intelligent states we compare exact solutions with analytical approximations in two limiting cases.Comment: 20 pages, 9 figures, submitted to J. Opt. B special issue in connection with ICSSUR 2005 conferenc

Parametric Evolution for a Deformed Cavity

We consider a classically chaotic system that is described by a Hamiltonian H(Q,P;x), where (Q,P) describes a particle moving inside a cavity, and x controls a deformation of the boundary. The quantum-eigenstates of the system are |n(x)>. We describe how the parametric kernel P(n|m) = , also known as the local density of states, evolves as a function of x-x0. We illuminate the non-unitary nature of this parametric evolution, the emergence of non-perturbative features, the final non-universal saturation, and the limitations of random-wave considerations. The parametric evolution is demonstrated numerically for two distinct representative deformation processes.Comment: 13 pages, 8 figures, improved introduction, to be published in Phys. Rev.

Entangled light from Bose-Einstein condensates

We propose a method to generate entangled light with a Bose-Einstein condensate trapped in a cavity, a system realized in recent experiments. The atoms of the condensate are trapped in a periodic potential generated by a cavity mode. The condensate is continuously pumped by a laser and spontaneously emits a pair of photons of different frequencies in two distinct cavity modes. In this way, the condensate mediates entanglement between two cavity modes which leak out and can be separated and exhibit continuous variable entanglement. The scheme exploits the experimentally demonstrated strong, steady and collective coupling of condensate atoms to a cavity field.Comment: 5 pages and 5 figure