967 research outputs found

    Perspectives for a mixed two-qubit system with binomial quantum states

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    The problem of the relationship between entanglement and two-qubit systems in which it is embedded is central to the quantum information theory. This paper suggests that the concurrence hierarchy as an entanglement measure provides an alternative view of how to think about this problem. We consider mixed states of two qubits and obtain an exact solution of the time-dependent master equation that describes the evolution of two two-level qubits (or atoms) within a perfect cavity for the case of multiphoton transition. We consider the situation for which the field may start from a binomial state. Employing this solution, the significant features of the entanglement when a second qubit is weakly coupled to the field and becomes entangled with the first qubit, is investigated. We also describe the response of the atomic system as it varies between the Rabi oscillations and the collapse-revival mode and investigate the atomic inversion and the Q-function. We identify and numerically demonstrate the region of parameters where significantly large entanglement can be obtained. Most interestingly, it is shown that features of the entanglement is influenced significantly when the multi-photon process is involved. Finally, we obtain illustrative examples of some novel aspects of this system and show how the off-resonant case can sensitize entanglement to the role of initial state setting.Comment: 18 pages, 9 figure

    GLP-1R Agonist Liraglutide Activates Cytoprotective Pathways and Improves Outcomes After Experimental Myocardial Infarction in Mice

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    OBJECTIVE—Glucagon-like peptide-1 receptor (GLP-1R) ago-nists are used to treat type 2 diabetes, and transient GLP-1 administration improved cardiac function in humans after acute myocardial infarction (MI) and percutaneous revascularization. However, the consequences of GLP-1R activation before isch-emic myocardial injury remain unclear. RESEARCH DESIGN AND METHODS—We assessed the pathophysiology and outcome of coronary artery occlusion in normal and diabetic mice pretreated with the GLP-1R agonist liraglutide. RESULTS—Male C57BL/6 mice were treated twice daily for 7 days with liraglutide or saline followed by induction of MI. Survival was significantly higher in liraglutide-treated mice. Lira-glutide reduced cardiac rupture (12 of 60 versus 46 of 60; P 0.0001) and infarct size (21 2 % versus 29 3%, P 0.02) an

    Elliptic flow of electrons from heavy-flavor hadron decays in Au+Au collisions at sNN=\sqrt{s_{\rm NN}} = 200, 62.4, and 39 GeV

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    We present measurements of elliptic flow (v2v_2) of electrons from the decays of heavy-flavor hadrons (eHFe_{HF}) by the STAR experiment. For Au+Au collisions at sNN=\sqrt{s_{\rm NN}} = 200 GeV we report v2v_2, for transverse momentum (pTp_T) between 0.2 and 7 GeV/c using three methods: the event plane method (v2v_{2}{EP}), two-particle correlations (v2v_2{2}), and four-particle correlations (v2v_2{4}). For Au+Au collisions at sNN\sqrt{s_{\rm NN}} = 62.4 and 39 GeV we report v2v_2{2} for pT<2p_T< 2 GeV/c. v2v_2{2} and v2v_2{4} are non-zero at low and intermediate pTp_T at 200 GeV, and v2v_2{2} is consistent with zero at low pTp_T at other energies. The v2v_2{2} at the two lower beam energies is systematically lower than at sNN=\sqrt{s_{\rm NN}} = 200 GeV for pT<1p_T < 1 GeV/c. This difference may suggest that charm quarks interact less strongly with the surrounding nuclear matter at those two lower energies compared to sNN=200\sqrt{s_{\rm NN}} = 200 GeV.Comment: Version accepted by PR
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