Bell inequality violation by entangled single photon states generated from a laser, a LED or a Halogen lamp

In single-particle or intraparticle entanglement, two degrees of freedom of a single particle, e.g., momentum and polarization of a single photon, are entangled. Single-particle entanglement (SPE) provides a source of non classical correlations which can be exploited both in quantum communication protocols and in experimental tests of noncontextuality based on the Kochen-Specker theorem. Furthermore, SPE is robust under decoherence phenomena. Here, we show that single-particle entangled states of single photons can be produced from attenuated sources of light, even classical ones. To experimentally certify the entanglement, we perform a Bell test, observing a violation of the Clauser, Horne, Shimony and Holt (CHSH) inequality. On the one hand, we show that this entanglement can be achieved even in a classical light beam, provided that first-order coherence is maintained between the degrees of freedom involved in the entanglement. On the other hand, we prove that filtered and attenuated light sources provide a flux of independent SPE photons that, from a statistical point of view, are indistinguishable from those generated by a single photon source. This has important consequences, since it demonstrates that cheap, compact, and low power entangled photon sources can be used for a range of quantum technology applications

Scalable Layer-2/Layer-3 Multistage Switching Architectures for Software Routers

Software routers are becoming an important alternative to proprietary and expensive network devices, because they exploit the economy of scale of the PC market and open-source software. When considering maximum performance in terms of throughput, PC-based routers suffer from limitations stemming from the single PC architecture, e.g., limited bus bandwidth, and high memory access latency. To overcome these limitations, in this paper we present a multistage architecture that combines a layer-2 load-balancer front-end and a layer-3 routing back-end, interconnected by standard Ethernet switches. Both the front-end and the back-end are implemented using standard PCs and open- source software. After describing the architecture, evaluation is performed on a lab test-bed, to show its scalability. While the proposed solution allows to increase performance of PC- based routers, it also allows to distribute packet manipulation functionalities, and to automatically recover from component failures

On the Observables Describing a Quantum Reference Frame

A reference frame F is described by the element g of the Poincare' group P which connects F with a given fixed frame F_0. If F is a quantum frame, defined by a physical object following the laws of quantum physics, the parameters of g have to be considered as quantum observables. However, these observables are not compatible and some of them, namely the coordinates of the origin of F, cannot be represented by self-adjoint operators. Both these difficulties can be overcome by considering a positive-operator-valued measure (POVM) on P, covariant with respect to the left translations of the group, namely a covariance system. We develop a construction procedure for this kind of mathematical structure. The formalism is also used to discuss the quantum observables measured with respect to a quantum reference frame.Comment: 23 pages, no figure

A Rigorous Approach to the Feynman-Vernon Influence Functional and its Applications. I

A rigorous representation of the Feynman-Vernon influence functional used to describe open quantum systems is given, based on the theory of infinite dimensional oscillatory integrals. An application to the case of the density matrices describing the Caldeira-Leggett model of two quantum systems with a quadratic interaction is treated

Energy Use Analysis for the Federal Energy Management Program

Recent congressional legislation allows federal agencies new authorities to contract for energy savings by sharing the acquired savings with an energy service company. As part of its charter to make the federal government more energy-efficient, the Federal Energy Management Program (FEMP) endeavors to improve the technical basis for such performance-based contracting. Specific tasks include the development of improved energy use baselining methods, refinement of a simplified energy analysis method and support to users, preparation of guidelines and procedures for energy savings initiatives, and publication of a manual to guide identification and analysis of energy conservation measures. This paper describes the current status and planned progress in each of these areas, and how these relate to several planned shared savings projects

Use of Metering for Facility and Whole Building Energy Analysis by the U.S. Depratment of Energy Federal Energy Management Program

This paper details how the U.S. Department of Energy, Federal Energy Management Program (FEMP) is applying metering technology to conduct empirically based analyses o f energy use by federal agencies. Continuing developments in sensors, data acquisition systems, microcomputers and monitoring protocols are reducing the costs of metering to the point that it is becoming "too cheap not to meter" energy and the determinants of energy use at federal facilities . This has widespread consequence for FEMP if one accepts the axiom that "one can't manage what one doesn't measure." Several recently completed and ongoing activities being managed by Pacific Northwest laboratory for FEMP are highlighted in this paper. This includes the metering of energy end uses for a research laboratory building to support a shared energy savings contract, analysis of utility billing records, climate, and characteristics data for entire military bases to prioritize energy use testing requirements, and enhancements to simplified energy analysis tools to help federal energy decision-makers identify and evaluate cost-effective energy savings opportunities

MUNICÍPIO RESILIENTE EM AFOGAMENTO

De acordo com a Organização Mundial da Saúde, afogamento é uma grave ameaça negligenciada à saúde pública, sendo que morrem em média 372.000 pessoas por ano em todo o mundo; 40 pessoas a cada hora do dia. No Brasil quase 1 milhão de pessoas se afogam e 5.700 morrem por afogamento a cada ano, sendo mais de 75% em rios, lagos e represas onde não existe nenhuma supervisão de guarda-vidas. Tendo em vista esta trágica realidade, é fundamental criar mecanismos de resiliência para estes locais, tendo como atores centrais os municípios, de forma a melhor efetivarem a gestão de riscos de afogamento em suas áreas geográficas

Synthesis of Majorana mass terms in low-energy quantum systems

We discuss the problem of how Majorana mass terms can be generated in low-energy systems. We show that, while these terms imply the Majorana condition, the opposite is not always true when more than one flavour is involved. This is an important aspect for the low-energy realizations of the Majorana mass terms exploiting superfluid pairings, because in this case the Majorana condition is not implemented in the spinor space, but in an internal (flavour) space. Moreover, these mass terms generally involve opposite effective chiralities, similarly to a Dirac mass term. The net effect of these features is that the Majorana condition does not imply a Majorana mass term. Accordingly the obtained Majorana spinors, as well as the resulting symmetry breaking pattern and low-energy spectrum, are qualitatively different from the ones known in particle physics. This result has important phenomenological consequences, e.g. implies that these mass terms are unsuitable to induce an effective see-saw mechanism, proposed to give mass to neutrinos. Finally, we introduce and discuss schemes based on space-dependent pairings with nonzero total momentum to illustrate how genuine Majorana mass terms may emerge in low-energy quantum systems