A quantum-mechanical treatment of Szilard's engine: Implications for the entropy of information

We present a quantum-mechanical analysis of Szilard's famous single-molecule engine, showing that it is analogous to the double-slit experiment. We further show that the energy derived from the engine's operation is provided by the act of observing the molecule's location. The engine can be operated with no increase in physical entropy, and the second law of thermodynamics does not compel us to relate physical entropy to informational entropy. We conclude that information per seis a subjective, idealized, concept separated from the physical realm. Physical entropy depends on physical objects and physical interactions, and any entropy change owing to observations is entirely a result of the entropy created in the physical apparatus by the process of observation.     

Theorem relating spatial and temporal harmonics for nuclear interlevel transfer driven by collective electronic oscillation

A crucial step in the development of gamma-ray lasers will be the discovery of an efficient mechanism for nuclear interlevel transfer. One promising mechanism uses the near-field interaction between the nucleus and laser-driven collective electronic oscillations. I prove an important theorem relating spatial and temporal harmonics: 2²ⁿ-poles are driven only at even multiples of the laser frequency, while 2²ⁿ⁺¹-poles are driven only at odd multiples of the laser frequency. I comment on the theorem's relevance to a proposed interlevel-transfer experiment.     

Laser coupling to nuclei via collective electronic oscillations—a simple heuristic model study

The induction field coupling of laser-driven collective electronic oscillations has been proposed as an interlevel transfer mechanism for a gamma-ray laser. Using a heuristic classical model for the electron oscillations, we verify in the model six general features which we conjecture are valid for laser-induced collective oscillations: (1) enhancement of the electric field seen by the nucleus, (2) harmonic generation, (3) generation of higher multipoles, (4) odd (even) order multipoles couple to odd (even) harmonics, (5) there exists an optimum laser intensity for each multipole order and harmonic, and (6) for a given multipole order, the optimum intensity increases with harmonic number. We briefly discuss the relevance of these results to a proposed interlevel transfer experiment in ²³⁵U.     

High resolution of human lactate dehydrogenase: new multiple forms and potential tumor markers

Human lactate dehydrogenase (LDH) was investigated by ultrathin-layer polyacrylamide gel isoelectric focusing (IEF). In serum, approximately 15 bands and in lyzates of erythrocytes approximately 20 bands were detected. Known LDH isoenzymes (identified by markers) appeared in the zymograms as follows: LDH-1 as a single or double band, LDH-2 as a single band in serum and in the marker, and as a double band in hemolyzate, LDH-3 as a double band, and LDH-4 and LDH-5 each as a single band. LDH-1 was partly inactivated, probably due to deamidation in the acidic range of the pH gradient. Potential LDH tumor markers were detected in different tumor cytosols.     

Status of research in gamma-ray lasers

This article reviews conceptual devices designed to generate coherent high-quantum-energy radiation by stimulating nuclear transitions in solids; and delineates some of the promising areas of research. Solid state γ-ray lasers can benefit from (1) Mössbauer effect or recoilless emission, which suppresses first-order Doppler broadening, and brings the emitting nuclei close to a common resonant frequency; and (2) Borrmann effect, which suppresses non-resonant scattering and absorption, and may allow a crystal lattice to act as a distributed resonator. I discuss some of the basic physics that governs the performance of conceptual γ-ray lasers, and some of the classic approaches to design. Many of these early schemes were shown to be unworkable decades ago, but re-emerge in different forms generally without attention to the fallacies already revealed. Other schemes have languished for lack of a champion. I also describe some exciting new approaches, particularly those utilizing techniques for suppressing resonant absorption, which can realize gain without a true inversion. Finally, I submit some recommendations for future research.     

Understanding geometrical phases in quantum mechanics: An elementary example

We discuss an exact solution to the simplest nontrivial example of a geometrical phase in quantum mechanics. By means of this example: (1) we elucidate the fundamental distinction between rays and vectors in describing quantum mechanical states; (2) we show that superposition of quantal states is invalid; only decomposition is allowed—which is adequate for the measurement process. Our example also shows that the origin of singularities in the analog vector potential is to be found in the unavoidable breaking of projective symmetry caused by using the Schrödinger equation.To Professor Asim O. Barut on the occasion of his 65th birthday.     

Stability analysis for multi-parameter linear periodic systems

Summary This paper is devoted to stability analysis of general linear periodic systems depending on real parameters. The Floquet method and perturbation technique are the basis of the development. We start out with the first and higher-order derivatives of the Floquet matrix with respect to problem parameters. Then the behaviour of simple and multiple multipliers of the system with a change of parameters is studied. Weak and strong interactions of multipliers in the complex plane are treated separately. The presented theory is exemplified and discussed. Received 27 April 1998; accepted for publication 5 November 1998     

The futility of observing stimulated gamma-ray emission from a long-lived isomeric state

Summary We reveal the fallacies in recent gamma-ray laser schemes that propose to obtain gain by stimulating transitions from a long-lived upper to a short-lived lower nuclear state. We point out the errors in recent derivations of the stimulated-emission coefficients, derive the correct formulae, and submit an alternative explanation for an experiment purported to observe stimulated emission from a long-lived isomer.