Physical limitations on quantum nonlocality in the detection of gamma photons emitted from positron/electron annihilation

Recent experimental measurements of the time interval between detection of the two photons emitted in positron/electron annihilation have indicated that collapse of the spatial part of the photon's wavefunction, due to detection of the other photon, does not occur. Although quantum nonlocality actually occurs in photons produced through parametric down-conversion, the recent experiments give strong evidence against measurement-induced instantaneous spatial-localization of high-energy gamma photons. A new quantum-mechanical analysis of the EPR problem is presented which may help to explain the observed differences between photons produced through parametric down-conversion and photons produced through positron/electron annihilation. The results are found to concur with the recent experiments involving gamma photons.Comment: accepted for publication, Phys. Rev.

National Interprofessional Education Initiatives

Purpose: The goal of this presentation is to define the IPE activities that meet the national competencies and share strategies for designing, implementing, and assessing IPE programs. Background: According to the World Health Organization (WHO), interprofessional education is defined as students from 2 or more professions learning about, from, and with each other to enable effective collaborations and improve health outcomes. The institute of Medicine (IOM) reports that IPE must be included in the education and training of health care professionals to enhance the delivery of health care services. Most recently, many accrediting agencies have refined IPE to be Interprofessional Practice and Education. Accreditation Council for Pharmacy Education (ACPE) included IPE in the 2016 Accreditation Standards. Many colleges and schools of pharmacy have successfully developed and implemented IPE programs at their institutions. Description of Intervention: Faculty and administrators from various U.S. pharmacy programs will describe didactic and experiential IPE programs at their institutions. The presenters will share innovative examples of IPE programs and provide “lessons learned” for developing, implementing, and assessing IPE programs. Results: A group of academicians will highlight their national IPE initiatives to better meet the WHO framework, International Pharmaceutical Federation (FIP) Global Competencies, and ACPE standards. In addition, the presenters will describe innovative strategies for designing, implementing, and assessing the quality of IPE programs in various schools and colleges of pharmacy. Conclusions: Re-designing the education and training of health care professionals by including IPE will enhance the quality and safety of health care services, reduce costs, and improve health outcomes. Relevance to IPE or Practice: Initiatives used to design, implement, and assess various IPE programs can be applied to other healthcare disciplines delivering IPE. Educational and training outcomes of these initiatives can be mapped to national and global IPE standards to enhance the quality of pharmacy education. Learning Objectives: 1. Describe various national programs for designing, implementing, and assessing IPE. 2. Identify successful examples of IPE pharmacy programs applicable to other health care professions. 3. Share “lessons learned” for designing, implementing, and assessing IPE programs

Experimental Demonstration of a Quantum Circuit using Linear Optics Gates

One of the main advantages of an optical approach to quantum computing is the fact that optical fibers can be used to connect the logic and memory devices to form useful circuits, in analogy with the wires of a conventional computer. Here we describe an experimental demonstration of a simple quantum circuit of that kind in which two probabilistic exclusive-OR (XOR) logic gates were combined to calculate the parity of three input qubits.Comment: v2 is final PRA versio

Optimization of Bell's Inequality Violation For Continuous Variable Systems

Two mode squeezed vacuum states allow Bell's inequality violation (BIQV) for all non-vanishing squeezing parameter $(\zeta)$. Maximal violation occurs at $\zeta \to \infty$ when the parity of either component averages to zero. For a given entangled {\it two spin} system BIQV is optimized via orientations of the operators entering the Bell operator (cf. S. L. Braunstein, A. Mann and M. Revzen: Phys. Rev. Lett. {\bf68}, 3259 (1992)). We show that for finite $\zeta$ in continuous variable systems (and in general whenever the dimensionality of the subsystems is greater than 2) additional parameters are present for optimizing BIQV. Thus the expectation value of the Bell operator depends, in addition to the orientation parameters, on configuration parameters. Optimization of these configurational parameters leads to a unique maximal BIQV that depends only on $\zeta.$ The configurational parameter variation is used to show that BIQV relation to entanglement is, even for pure state, not monotonic.Comment: An example added; shows that the amount of Bell's inequality violation as a measure of entanglement is doubtfu

Practical Quantum Bit Commitment Protocol

A quantum protocol for bit commitment the security of which is based on technological limitations on nondemolition measurements and long-term quantum memory is presented.Comment: Quantum Inf. Process. (2011

Probabilistic Quantum Encoder for Single-Photon Qubits

We describe an experiment in which a physical qubit represented by the polarization state of a single-photon was probabilistically encoded in the logical state of two photons. The experiment relied on linear optics, post-selection, and three-photon interference effects produced by a parametric down-conversion photon pair and a weak coherent state. An interesting consequence of the encoding operation was the ability to observe entangled three-photon Greenberger-Horne-Zeilinger states.Comment: 4 pages, 4 figures; submitted to Phys. Rev.

Full Quantum Analysis of Two-Photon Absorption Using Two-Photon Wavefunction: Comparison with One-Photon Absorption

For dissipation-free photon-photon interaction at the single photon level, we analyze one-photon transition and two-photon transition induced by photon pairs in three-level atoms using two-photon wavefunctions. We show that the two-photon absorption can be substantially enhanced by adjusting the time correlation of photon pairs. We study two typical cases: Gaussian wavefunction and rectangular wavefunction. In the latter, we find that under special conditions one-photon transition is completely suppressed while the high probability of two-photon transition is maintained.Comment: 6 pages, 4 figure

Non-realism : deep thought or a soft option ?

The claim that the observation of a violation of a Bell inequality leads to an alleged alternative between nonlocality and non-realism is annoying because of the vagueness of the second term.Comment: 5 page