8,265 research outputs found

    Demystifying “Pornography”: Tailoring Special Release Conditions Concerning Pornography and Sexually Oriented Expression

    Get PDF
    [Excerpt] “This article examines the design of special release conditions and the problems that arise when such conditions do not comport with constitutional standards. Part I provides a general overview of the First Amendment issues that often arise with respect to special release conditions. Part II discusses the current state of the law and classifies the types of bans defendants have encountered in supervised release conditions. Part III explains the factors that are frequently considered in assessing the validity of special release conditions, and Part IV suggests a new approach for evaluating the constitutionality of special release conditions. The article concludes by endorsing constitutionally permissible tailoring for release conditions and by encouraging courts to interpret these conditions with careful attention to the individual defendant’s situation.

    Entanglement sudden death and sudden birth in two uncoupled spins

    Full text link
    We investigate the entanglement evolution of two qubits interacting with a common environment trough an Heisenberg XX mechanism. We reveal the possibility of realizing the phenomenon of entanglement sudden death as well as the entanglement sudden birth acting on the environment. Such analysis is of maximal interest at the light of the large applications that spin systems have in quantum information theory

    Sensitivity of Measurement-Based Purification Processes to Inner Interactions

    Full text link
    The sensitivity of a repeated measurement-based purification scheme to additional undesired couplings is analyzed, focusing on the very simple and archetypical system consisting of two two-level systems interacting with a repeatedly measured one. Several regimes are considered and in the strong coupling (i.e., when the coupling constant of the undesired interaction is very large) the occurrence of a quantum Zeno effect is proven to dramatically jeopardize the efficiency of the purification process.Comment: 12 pages, 6 figure

    Derivative markets and competitiveness

    Get PDF
    Swaps (Finance) ; Futures ; Foreign exchange

    A criterion for entanglement in two two-level systems

    Full text link
    We prove a necessary and sufficient condition for the occurrence of entanglement in two two-level systems, simple enough to be of experimental interest. Our results are illustrated in the context of a spin star system analyzing the exact entanglement evolution of the central couple of spins.Comment: 4 pages, Submitted to Physical Review Letter

    Loss induced collective subradiant Dicke behaviour in a multiatom sample

    Full text link
    The exact dynamics of NN two-level atoms coupled to a common electromagnetic bath and closely located inside a lossy cavity is reported. Stationary radiation trapping effects are found and very transparently interpreted in the context of our approach. We prove that initially injecting one excitation only in the NN atoms-cavity system, loss mechanisms asymptotically drive the matter sample toward a long-lived collective subradiant Dicke state. The role played by the closeness of the NN atoms with respect to such a cooperative behavior is brought to light and carefully discussed.Comment: 14 pages, 6 figures, submitted to EPJ

    Revealing non-classical behaviours in the oscillatory motion of a trapped ion

    Full text link
    The possibility of revealing non-classical behaviours in the dynamics of a trapped ion via measurements of the mean value of suitable operators is reported. In particular we focus on the manifestation known as `` Parity Effect\rq\rq which may be observed \emph{directly measuring} the expectation value of an appropriate correlation operator. The experimental feasibility of our proposal is discussed.Comment: 5 pages, 2 figure

    Quantum Phase Transitions and Heat Capacity in a two-atoms Bose-Hubbard Model

    Full text link
    We show that a two-atoms Bose-Hubbard model exhibits three different phases in the behavior of thermal entanglement in its parameter space. These phases are demonstrated to be traceable back to the existence of quantum phase transitions in the same system. Significant similarities between the behaviors of thermal entanglement and heat capacity in the parameter space are brought to light thus allowing to interpret the occurrence and the meaning of all these three phases.Comment: 6 pages, 3 figure

    Interaction of bimodal fields with few-level atoms in cavities and traps

    Get PDF
    The spectacular experimental results of the last few years in cavity quantum electrodynamics and trapped ions research has led to very high level laboratory performances. Such a stimulating situation essentially stems from two decisive advancements. The first is the invention of reliable protocols for the manipulation of single atoms. The second is the ability to produce desired bosonic environments on demand. These progresses have led to the possibility of controlling the form of the coupling between individual atoms and an arbitrary number of bosonic modes. As a consequence, fundamental matter-radiation interaction models like, for instance, the JC model and most of its numerous nonlinear multiphoton generalizations, have been realized or simulated in laboratory and their dynamical features have been tested more or less in detail. This topical paper reviews the state of the art of the theoretical investigations and of the experimental observations concerning the dynamical features of the coupling between single few-level atoms and two bosonic modes. In the course of the paper we show that such a configuration provides an excellent platform for investigating various quantum intermode correlation effects tested or testable in the cavity quantum electrodynamics and trapped ion experimental realms. In particular we discuss a mode-mode correlation effect appearing in the dynamics of a two-level atom quadratically coupled to two bosonic modes. This effect, named parity effect, consists in a high sensitivity to the evenness or oddness of the total number of bosonic excitations.Comment: Topical Review. To appear on J. Mod. Op
    corecore