Emergence of the pointer basis through the dynamics of correlations

We use the classical correlation between a quantum system being measured and its measurement apparatus to analyze the amount of information being retrieved in a quantum measurement process. Accounting for decoherence of the apparatus, we show that these correlations may have a sudden transition from a decay regime to a constant level. This transition characterizes a non-asymptotic emergence of the pointer basis, while the system-apparatus can still be quantum correlated. We provide a formalization of the concept of emergence of a pointer basis in an apparatus subject to decoherence. This contrast of the pointer basis emergence to the quantum to classical transition is demonstrated in an experiment with polarization entangled photon pairs.Comment: 4+2 pgs, 3 figures. Title changed. Revised version to appear on PR

Granular circulation in a cylindrical pan: simulations of reversing radial and tangential flows

Granular flows due to simultaneous vertical and horizontal excitations of a flat-bottomed cylindrical pan are investigated using event-driven molecular dynamics simulations. In agreement with recent experimental results, we observe a transition from a solid-like state, to a fluidized state in which circulatory flow occurs simultaneously in the radial and tangential directions. By going beyond the range of conditions explored experimentally, we find that each of these circulations reverse their direction as a function of the control parameters of the motion. We numerically evaluate the dynamical phase diagram for this system and show, using a simple model, that the solid-fluid transition can be understood in terms of a critical value of the radial acceleration of the pan bottom; and that the circulation reversals are controlled by the phase shift relating the horizontal and vertical components of the vibrations. We also discuss the crucial role played by the geometry of the boundary conditions, and point out a relationship of the circulation observed here and the flows generated in vibratory conveyors.Comment: 10 pages, 8 figure

Should I stay or should I go? Patient understandings of and responses to source-isolation practices

Isolation of patients, who are colonised or infected with a multidrug-resistant organism (source-isolation), is a common practice in most acute health-care settings, to prevent transmission to other patients. Efforts to improve the efficacy of source-isolation in hospitals focus on healthcare staff compliance with isolation precautions. In this article we examine patients’ awareness, understandings and observance of source-isolation practices and directives with a view to understanding better the roles patients play or could play in transmitting, or limiting transmission, of multidrug-resistant organisms (MRO). Seventeen source-isolated adult surgical patients and two relatives participated in video-reflexive ethnography and interviews. We learned that, although most of these patients wanted to protect themselves and others from colonisation/infection with a MRO, they had a limited understanding of what precautions they could take while in isolation and found it difficult to obtain ongoing information. Thus, many patients regularly left their source-isolation rooms without taking appropriate precautions and were potentially contributing to environmental contamination and transmission. Some patients also interacted with other patients and their personal belongings in ways that exposed other patients, unnecessarily, to colonisation/infection risk. By not providing patients with adequate information on infection risk or how they could contribute to their own safety or that of others, they are denied the opportunity to fully engage in their healthcare. To improve the efficacy of source-isolation and contact precautions in general, patient care providers should consider colonised or infected patients as active partners in reducing transmission and involve patients and relatives in regular, ongoing conversations about transmission prevention

Incoherent non-Fermi liquid scattering in a Kondo lattice

One of the most notorious non-Fermi liquid properties of both archetypal heavy-fermion systems [1-4] and the high-Tc copper oxide superconductors [5] is an electrical resistivity that evolves linearly with temperature, T. In the heavy-fermion superconductor CeCoIn5 [5], this linear behaviour was one of the first indications of the presence of a zero-temperature instability, or quantum critical point. Here, we report the observation of a unique control parameter of T-linear scattering in CeCoIn5, found through systematic chemical substitutions of both magnetic and non-magnetic rare-earth, R, ions into the Ce sub-lattice. We find that the evolution of inelastic scattering in Ce1-xRxCoIn5 is strongly dependent on the f-electron configuration of the R ion, whereas two other key properties -- Cooper-pair breaking and Kondo-lattice coherence -- are not. Thus, T-linear resistivity in CeCoIn5 is intimately related to the nature of incoherent scattering centers in the Kondo lattice, which provides insight into the anomalous scattering rate synonymous with quantum criticality [7].Comment: 4 pages, 3 figures (published version

Transfer?ncia de tecnologia como agente desenvolvedor da cultura de inova??o na UFMG.

O presente trabalho tem por objeto as pol?ticas de fomento ? transfer?ncia de tecnologias a partir da ?tica da gest?o de patentes, tipo de inova??o das tecnologias desenvolvidas e grau de participa??o empreendedora de docentes. Para tanto, foi realizado um estudo de caso em que foi realizada uma an?lise descritiva do N?cleo de Inova??o da UFMG, visando identificar e analisar a pertin?ncia das tecnologias produzidas pela UFMG entre 2012 a 2017. A escolha da UFMG como fonte de dados se deu por esta institui??o apresentar a maior quantidade de patentes registradas no Brasil e tamb?m por se tratar da institui??o a que dois dos pesquisadores est?o afiliados. Os resultados apontam que, investindo em transfer?ncias de tecnologias, a institui??o fomenta a cultura da inova??o, fortalecendo tamb?m a cultura empreendedora e a preocupa??o com a prote??o de tecnologias.This study's purpose is promotion of policies for technology transfer from the perspective of patent management, kind of innovation of technologies developed and degree of entrepreneurial participation of teachers. A case study was carried out in which a descriptive analysis of the Innovation Center of UFMG was carried out to identify and analyze the relevance of the technologies produced by UFMG between 2012 and 2017. The choice of UFMG as data source was given by this institution presents the largest number of patents registered in Brazil and also because it is the institution to which two of the researchers are affiliated. The results show that by investing in technology transfer, the institution fosters a culture of innovation, also strengthening the entrepreneurial culture and concern for the protection technologies

Simulations of events for the LUX-ZEPLIN (LZ) dark matter experiment

The LUX-ZEPLIN dark matter search aims to achieve a sensitivity to the WIMP-nucleon spin-independent cross-section down to (1–2)×10−12 pb at a WIMP mass of 40 GeV/c2. This paper describes the simulations framework that, along with radioactivity measurements, was used to support this projection, and also to provide mock data for validating reconstruction and analysis software. Of particular note are the event generators, which allow us to model the background radiation, and the detector response physics used in the production of raw signals, which can be converted into digitized waveforms similar to data from the operational detector. Inclusion of the detector response allows us to process simulated data using the same analysis routines as developed to process the experimental data