Entanglement Sharing in the Two-Atom Tavis-Cummings Model

Individual members of an ensemble of identical systems coupled to a common probe can become entangled with one another, even when they do not interact directly. We investigate how this type of multipartite entanglement is generated in the context of a system consisting of two two-level atoms resonantly coupled to a single mode of the electromagnetic field. The dynamical evolution is studied in terms of the entanglements in the different bipartite partitions of the system, as quantified by the I-tangle. We also propose a generalization of the so-called residual tangle that quantifies the inherent three-body correlations in our tripartite system. This enables us to completely characterize the phenomenon of entanglement sharing in the case of the two-atom Tavis-Cummings model, a system of both theoretical and experimental interest.Comment: 11 pages, 4 figures, submitted to PRA, v3 contains corrections to small error

An algebraic approach to the Tavis-Cummings problem

An algebraic method is introduced for an analytical solution of the eigenvalue problem of the Tavis-Cummings (TC) Hamiltonian, based on polynomially deformed su(2), i.e. su_n(2), algebras. In this method the eigenvalue problem is solved in terms of a specific perturbation theory, developed here up to third order. Generalization to the N-atom case of the Rabi frequency and dressed states is also provided. A remarkable enhancement of spontaneous emission of N atoms in a resonator is found to result from collective effects.Comment: 13 pages, 7 figure

Phenomenology of the nMSSM from colliders to cosmology

Low energy supersymmetric models provide a solution to the hierarchy problem and also have the necessary ingredients to solve two of the most outstanding issues in cosmology: the origin of dark matter and baryonic matter. One of the most attractive features of this framework is that the relevant physical processes are related to interactions at the weak scale and therefore may be tested in collider experiments in the near future. This is true for the Minimal Supersymmetric Standard Model (MSSM) as well as for its extension with the addition of one singlet chiral superfield, the so-called nMSSM. It has been recently shown that within the nMSSM an elegant solution to both the problem of baryogenesis and dark matter may be found, that relies mostly on the mixing of the singlet sector with the Higgs sector of the theory. In this work we review the nMSSM model constraints from cosmology and present the associated collider phenomenology at the LHC and the ILC. We show that the ILC will efficiently probe the neutralino, chargino and Higgs sectors, allowing to confront cosmological observations with computations based on collider measurements. We also investigate the prospects for a direct detection of dark matter and the constraints imposed by the current bounds of the electron electric dipole moment in this model.Comment: 44 pp, 10 figures; Fig.9 replaced; discussion on CP violation extended and references added; few minor additions in text about details of the cut

Mitral valve annulus dimensions assessment with three-dimensional echocardiography versus computed tomography: implications for transcatheter interventions

The aim of this study is to evaluate the agreement between three-dimensional (3D) transesophageal echocardiography (TEE) and multidetector computed tomography (MDCT) for assessing mitral annular (MA) dimensions. A total of 105 patients (79 +/- 9 years old, 52% male) who underwent clinically indicated 3D TEE and MDCT feasible for MA geometrical assessment were included. Using dedicated semi-automated postprocessing software, MA geometry, including mitral annular area (MAA), perimeter, septal-lateral (SL) diameter, and inter-trigonal (TT) diameter, was evaluated using 3D TEE and MDCT. Compared to 3D TEE, MAA, perimeter, and SL distance measured on MDCT data were larger (9.9 +/- 3.0 vs. 9.3 +/- 3.1 cm(2) for MAA; 115 +/- 18 vs. 108 +/- 18 mm for perimeter; and 35 +/- 5 vs. 32 +/- 5 cm for SL distance, all p < 0.001). By contrast, the TT distance was comparable between MDCT and 3D TEE (26 +/- 4 vs. 26 +/- 4 cm, p = 0.258). The correlations of all the MA dimensions were good to excellent between the two modalities (R = 0.911 for MAA, 0.890 for perimeter, 0.739 for TT distance, and 0.857 for SL distance, respectively, all p < 0.001). This study showed good agreement between 3D TEE- and MDCT-derived MA measurements although MDCT systematically provided larger MAA, perimeter, and SL distance compared with 3D TEE.Cardiolog

Family Unification on an Orbifold

We construct a family-unified model on a Z_2xZ_2 orbifold in five dimensions. The model is based on a supersymmetric SU(7) gauge theory. The gauge group is broken by orbifold boundary conditions to a product of grand unified SU(5) and SU(2)xU(1) flavor symmetry. The structure of Yukawa matrices is generated by an interplay between spontaneous breaking of flavor symmetry and geometric factors arising due to field localization in the extra dimension.Comment: 13 page

Assessment of left atrial electro-mechanical delay to predict atrial fibrillation in hypertrophic cardiomyopathy

Aims Atrial fibrillation (AF) is frequently observed in hypertrophic cardiomyopathy (HCM) and is associated with poor clinical outcome. Total atrial conduction time, estimated by tissue Doppler imaging (TDI), the so-called PA-TDI duration, reflects the left atrial (LA) structural and electrical remodelling. The aim of this study was to evaluate the association between PA-TDI and new-onset AF in patients with HCM.Methods and results From a large cohort of patients with HCM, 208 patients (64% male, mean age 53 +/- 14 years) without AF were selected. PA-TDI duration was measured from the onset P wave on electrocardiogram to the peak A' wave of the lateral LA wall using TDI. The incidence of new-onset AF was 20% over a median follow-up of 7.3 (3.5-10.5) years. Patients with incident AF had longer PA-TDI duration when compared with patients without AF (133.7 +/- 23.0 vs. 110.5 +/- 30.0 ms, P < 0.001). PA-TDI duration was independently associated with new-onset AF (hazard ratio: 1.03, 95% confidence interval: 1.01-1.05, P < 0.001).Conclusion Prolonged PA-TDI duration was independently associated with new-onset AF in patients with HCM. This novel parameter could be useful to risk-stratify patients with HCM who are at risk of having AF.Cardiolog

Quantum criticalities in a two-leg antiferromagnetic S=1/2 ladder induced by a staggered magnetic field

We study a two-leg antiferromagnetic spin-1/2 ladder in the presence of a staggered magnetic field. We consider two parameter regimes: strong (weak) coupling along the legs and weak (strong) coupling along the rungs. In both cases, the staggered field drives the Haldane spin-liquid phase of the ladder towards a Gaussian quantum criticality. In a generalized spin ladder with a non-Haldane, spontaneously dimerized phase, the staggered magnetic field induces an Ising quantum critical regime. In the vicinity of the critical lines, we derive low-energy effective field theories and use these descriptions to determine the dynamical response functions, the staggered spin susceptibility and the string order parameter.Comment: 29 pages of revtex, 10 figure

Computed tomography-derived transesophageal echocardiographic views step forward for procedural planning of transcatheter tricuspid valve annuloplasty

Cardiolog

An intermittent extreme BL Lac: MWL study of 1ES 2344+514 in an enhanced state

Extreme high-frequency BL Lacs (EHBL) feature their synchrotron peak of the broad-band spectral energy distribution (SED) at vs ≥ 1017 Hz. The BL Lac object 1ES 2344+514 was included in the EHBL family because of its impressive shift of the synchrotron peak in 1996. During the following years, the source appeared to be in a low state without showing any extreme behaviours. In 2016 August, 1ES 2344+514 was detected with the groundbased γ -ray telescope FACT during a high γ -ray state, triggering multiwavelength (MWL) observations. We studied the MWL light curves of 1ES 2344+514 during the 2016 flaring state, using data from radio to very-high-energy (VHE) γ -rays taken with OVRO, KAIT, KVA, NOT, some telescopes of the GASP-WEBT collaboration at the Teide, Crimean, and St. Petersburg observatories, Swift-UVOT, Swift-XRT, Fermi-LAT, FACT, and MAGIC. With simultaneous observations of the flare, we built the broad-band SED and studied it in the framework of a leptonic and a hadronic model. The VHE γ -ray observations show a flux level of 55 per cent of the Crab Nebula flux above 300 GeV, similar to the historical maximum of 1995. The combination of MAGIC and Fermi-LAT spectra provides an unprecedented characterization of the inverse-Compton peak for this object during a flaring episode. The _ index of the intrinsic spectrum in the VHE γ -ray band is 2.04 ± 0.12stat ± 0.15sys.We find the source in an extreme state with a shift of the position of the synchrotron peak to frequencies above or equal to 1018 Hz.The financial support of the German BMBF and MPG, the Italian INFN and INAF, the Swiss National Fund SNF, the ERDF under the Spanish MINECO (FPA2017-87859-P, FPA2017-85668-P, FPA2017-82729-C6-2-R, FPA2017-82729-C6-6-R, FPA2017-82729-C6-5-R, AYA2015-71042-P, AYA2016-76012-C3-1-P, ESP2017-87055-C2-2-P, and FPA2017-90566-REDC), the Indian Department of Atomic Energy, the Japanese JSPS and MEXT, the Bulgarian Ministry of Education and Science, National RI Roadmap Project DO1-153/28.08.2018, and the Academy of Finland grant no. 320045 is gratefully acknowledged. This work was also supported by the Spanish Centro de Excelencia ‘Severo Ochoa’ SEV-2016-0588 and SEV-2015-0548, and Unidad de Excelencia ‘María de Maeztu’ MDM-2014-0369, by the Croatian Science Foundation (HrZZ) Project IP-2016-06-9782 and the University of Rijeka Project 13.12.1.3.02, by the DFG Collaborative Research Centers SFB823/C4 and SFB876/C3, the Polish National Research Centre grant UMO-2016/22/M/ST9/00382 and by the Brazilian MCTIC, CNPq, and FAPERJ. The FACT collaboration acknowledges the important contributions from ETH Zurich grants ETH-10.08-2 and ETH-27.12-1 as well as the funding by the Swiss SNF and the German BMBF (Verbundforschung Astro- und Astroteilchenphysik) and HAP (Helmoltz Alliance for Astroparticle Physics) are gratefully acknowledged. Part of this work is supported by Deutsche Forschungsgemeinschaft (DFG) within the Collaborative Research Center SFB 876 ‘Providing Information by Resource-Constrained Analysis’, project C3

CD-based microfluidics for primary care in extreme point-of-care settings

We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis in extremely under-resourced environments. The various challenges faced in these settings are showcased, using areas in India and Africa as examples. Measures for the ability of integrated devices to effectively address point-of-care challenges are highlighted, and centrifugal, often termed CD-based microfluidic technologies, technologies are presented as a promising platform to address these challenges. We describe the advantages of centrifugal liquid handling, as well as the ability of a standard CD player to perform a number of common laboratory tests, fulfilling the role of an integrated lab-on-a-CD. Innovative centrifugal approaches for point-of-care in extremely resource-poor settings are highlighted, including sensing and detection strategies, smart power sources and biomimetic inspiration for environmental control. The evolution of centrifugal microfluidics, along with examples of commercial and advanced prototype centrifugal microfluidic systems, is presented, illustrating the success of deployment at the point-of-care. A close fit of emerging centrifugal systems to address a critical panel of tests for under-resourced clinic settings, formulated by medical experts, is demonstrated. This emphasizes the potential of centrifugal microfluidic technologies to be applied effectively to extremely challenging point-of-care scenarios and in playing a role in improving primary care in resource-limited settings across the developing world