2,513 research outputs found

    Epidermoid Cyst of Spleen

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    Splenic cysts are very rare lesions, most of them being parasitic systs. Nonparasitic cysts are uncommon. We report a case of young female who presented with mass and pain abdomen. Ultrasound examination revealed splenic syst. The diagnosis of epidermoid cyst was made based on characteristic lining on histopathological examinatio

    From quantum stochastic differential equations to Gisin-Percival state diffusion

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    Starting from the quantum stochastic differential equations of Hudson and Parthasarathy (Comm. Math. Phys. 93, 301 (1984)) and exploiting the Wiener-Ito-Segal isomorphism between the Boson Fock reservoir space Γ(L2(R+)⊗(Cn⊕Cn))\Gamma(L^2(\mathbb{R}_+)\otimes (\mathbb{C}^{n}\oplus \mathbb{C}^{n})) and the Hilbert space L2(μ)L^2(\mu), where μ\mu is the Wiener probability measure of a complex nn-dimensional vector-valued standard Brownian motion {B(t),t≥0}\{\mathbf{B}(t), t\geq 0\}, we derive a non-linear stochastic Schrodinger equation describing a classical diffusion of states of a quantum system, driven by the Brownian motion B\mathbf{B}. Changing this Brownian motion by an appropriate Girsanov transformation, we arrive at the Gisin-Percival state diffusion equation (J. Phys. A, 167, 315 (1992)). This approach also yields an explicit solution of the Gisin-Percival equation, in terms of the Hudson-Parthasarathy unitary process and a radomized Weyl displacement process. Irreversible dynamics of system density operators described by the well-known Gorini-Kossakowski-Sudarshan-Lindblad master equation is unraveled by coarse-graining over the Gisin-Percival quantum state trajectories.Comment: 28 pages, one pdf figure. An error in the multiplying factor in Eq. (102) corrected. To appear in Journal of Mathematical Physic

    Separability bounds on multiqubit moments due to positivity under partial transpose

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    Positivity of the density operator reflects itself in terms of sequences of inequalities on observable moments. Uncertainty relations for non-commuting observables form a subset of these inequalities. In addition, criterion of positivity under partial transposition (PPT) imposes distinct bounds on moments, violations of which signal entanglement. We present bounds on some novel sets of composite moments, consequent to positive partial transposition of the density operator and report their violation by entangled multiqubit states. In particular, we derive separability bounds on a multiqubit moment matrix (based on PPT constraints on bipartite divisions of the density matrix) and show that three qubit pure states with non-zero tangle violate these PPT moment constraints. Further, we recover necessary and sufficient condition of separability in a multiqubit Werner state through PPT bounds on moments.Comment: 16 pages, no figures, minor revisions, references added; To appear in Phys. Rev.

    A scheme for amplification and discrimination of photons

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    A scheme for exploring photon number amplification and discrimination is presented based on the interaction of a large number of two-level atoms with a single mode radiation field. The fact that the total number of photons and atoms in the excited states is a constant under time evolution in Dicke model is exploited to rearrange the atom-photon numbers. Three significant predictions emerge from our study: Threshold time for initial exposure to photons, time of perception (time of maximum detection probability), and discrimination of first few photon states.Comment: 8 pages, 3 figures, RevteX, Minor revision, References adde
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