6,126 research outputs found

    Perfect State Transfer, Effective Gates and Entanglement Generation in Engineered Bosonic and Fermionic Networks

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    We show how to achieve perfect quantum state transfer and construct effective two-qubit gates between distant sites in engineered bosonic and fermionic networks. The Hamiltonian for the system can be determined by choosing an eigenvalue spectrum satisfying a certain condition, which is shown to be both sufficient and necessary in mirror-symmetrical networks. The natures of the effective two-qubit gates depend on the exchange symmetry for fermions and bosons. For fermionic networks, the gates are entangling (and thus universal for quantum computation). For bosonic networks, though the gates are not entangling, they allow two-way simultaneous communications. Protocols of entanglement generation in both bosonic and fermionic engineered networks are discussed.Comment: RevTeX4, 6 pages, 1 figure; replaced with a more general example and clarified the sufficient and necessary condition for perfect state transfe

    ``Superfast'' Reaction in Turbulent Flow with Potential Disorder

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    We explore the regime of ``superfast'' reactivity that has been predicted to occur in turbulent flow in the presence of potential disorder. Computer simulation studies confirm qualitative features of the previous renormalization group predictions, which were based on a static model of turbulence. New renormalization group calculations for a more realistic, dynamic model of turbulence show that the superfast regime persists. This regime, with concentration decay exponents greater than that for a well-mixed reaction, appears to be a general result of the interplay among non-linear reaction kinetics, turbulent transport, and local trapping by potential disorder.Comment: 14 pages. 4 figures. Uses IOP styles. To appear in J. Phys. A: Math. Ge

    Schwinger Boson Formulation and Solution of the Crow-Kimura and Eigen Models of Quasispecies Theory

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    We express the Crow-Kimura and Eigen models of quasispecies theory in a functional integral representation. We formulate the spin coherent state functional integrals using the Schwinger Boson method. In this formulation, we are able to deduce the long-time behavior of these models for arbitrary replication and degradation functions. We discuss the phase transitions that occur in these models as a function of mutation rate. We derive for these models the leading order corrections to the infinite genome length limit.Comment: 37 pages; 4 figures; to appear in J. Stat. Phy

    Efficient electronic entanglement concentration assisted with single mobile electron

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    We present an efficient entanglement concentration protocol (ECP) for mobile electrons with charge detection. This protocol is quite different from other ECPs for one can obtain a maximally entangled pair from a pair of less-entangled state and a single mobile electron with a certain probability. With the help of charge detection, it can be repeated to reach a higher success probability. It also does not need to know the coefficient of the original less-entangled states. All these advantages may make this protocol useful in current distributed quantum information processing.Comment: 6pages, 3figure

    Spacetime Emergence and General Covariance Transmutation

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    Spacetime emergence refers to the notion that classical spacetime "emerges" as an approximate macroscopic entity from a non-spatio-temporal structure present in a more complete theory of interacting fundamental constituents. In this article, we propose a novel mechanism involving the "soldering" of internal and external spaces for the emergence of spacetime and the twin transmutation of general covariance. In the context of string theory, this mechanism points to a critical four dimensional spacetime background.Comment: 11 pages, v2: version to appear in MPL

    A Method to Tackle First Order Differential Equations with Liouvillian Functions in the Solution - II

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    We present a semi-decision procedure to tackle first order differential equations, with Liouvillian functions in the solution (LFOODEs). As in the case of the Prelle-Singer procedure, this method is based on the knowledge of the integrating factor structure.Comment: 11 pages, late

    Dispersion Coefficients by a Field-Theoretic Renormalization of Fluid Mechanics

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    We consider subtle correlations in the scattering of fluid by randomly placed obstacles, which have been suggested to lead to a diverging dispersion coefficient at long times for high Peclet numbers, in contrast to finite mean-field predictions. We develop a new master equation description of the fluid mechanics that incorporates the physically relevant fluctuations, and we treat those fluctuations by a renormalization group procedure. We find a finite dispersion coefficient at low volume fraction of disorder and high Peclet numbers.Comment: 4 pages, 1 figure; to appear in Phys. Rev. Let

    Mesoscopic colonization of a spectral band

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    We consider the unitary matrix model in the limit where the size of the matrices become infinite and in the critical situation when a new spectral band is about to emerge. In previous works the number of expected eigenvalues in a neighborhood of the band was fixed and finite, a situation that was termed "birth of a cut" or "first colonization". We now consider the transitional regime where this microscopic population in the new band grows without bounds but at a slower rate than the size of the matrix. The local population in the new band organizes in a "mesoscopic" regime, in between the macroscopic behavior of the full system and the previously studied microscopic one. The mesoscopic colony may form a finite number of new bands, with a maximum number dictated by the degree of criticality of the original potential. We describe the delicate scaling limit that realizes/controls the mesoscopic colony. The method we use is the steepest descent analysis of the Riemann-Hilbert problem that is satisfied by the associated orthogonal polynomials.Comment: 17 pages, 2 figures, minor corrections and addition

    The Bright and Dark Sides of High-Redshift starburst galaxies from {\it Herschel} and {\it Subaru} observations

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    We present rest-frame optical spectra from the FMOS-COSMOS survey of twelve z∼1.6z \sim 1.6 \textit{Herschel} starburst galaxies, with Star Formation Rate (SFR) elevated by ×\times8, on average, above the star-forming Main Sequence (MS). Comparing the Hα\alpha to IR luminosity ratio and the Balmer Decrement we find that the optically-thin regions of the sources contain on average only ∼10\sim 10 percent of the total SFR whereas ∼90\sim90 percent comes from an extremely obscured component which is revealed only by far-IR observations and is optically-thick even in Hα\alpha. We measure the [NII]6583_{6583}/Hα\alpha ratio, suggesting that the less obscured regions have a metal content similar to that of the MS population at the same stellar masses and redshifts. However, our objects appear to be metal-rich outliers from the metallicity-SFR anticorrelation observed at fixed stellar mass for the MS population. The [SII]6732_{6732}/[SII]6717_{6717} ratio from the average spectrum indicates an electron density ne∼1,100 cm−3n_{\rm e} \sim 1,100\ \mathrm{cm}^{-3}, larger than what estimated for MS galaxies but only at the 1.5σ\sigma level. Our results provide supporting evidence that high-zz MS outliers are the analogous of local ULIRGs, and are consistent with a major merger origin for the starburst event.Comment: 6 pages, 4 figures, Accepted for publication in ApJ Letter

    From job crafting to job quitting? Testing a wise proactivity perspective

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    Purpose: This study investigates when and for whom job crafting may turn into job quitting. The authors hypothesize that approach job crafting relates more positively to turnover intentions and subsequent voluntary job changes among employees with (a) high (vs low) need for career challenges and (b) those with high (vs low) self-esteem. Design/methodology/approach: Data were collected from 575 employees of a large public organization in the Netherlands with two measurement moments three months apart. Hypotheses were tested using cross-lagged regression analyses and path modeling. Findings: Supporting the hypotheses, approach crafting related positively to an increase in turnover intentions only among employees with high need for challenge or high self-esteem. Moreover, via turnover intentions at Time 1, approach crafting related positively to the voluntary job change at Time 2 for employees with (a) high need for challenge, as well as those with (b) high self-esteem. These findings held after controlling for avoidance crafting. Research limitations/implications: This study has been conducted in a relatively homogenous sample. Future research may test the predictions in a more heterogeneous sample, including participants from different cultural and economic contexts. Practical implications: The authors advise human resource (HR) professionals to facilitate the job crafting efforts of employees with a high need for challenge and those with high self-esteem because these groups are particularly at risk of voluntarily quitting their jobs. Adopting insights from the wise proactivity model may help ensure that job crafting benefits both employees and employers. Originality/value: This study brings clarity to the inconsistent relationships between job crafting and job quitting by using the wise proactivity model as an explanatory framework.</p
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