Entanglement generation via a completely mixed nuclear spin bath

We show that qubits coupled sequentially to a mesoscopic static completely mixed spin bath via the Heisenberg interaction can become highly entangled. Straightforward protocols for the generation of multipartite entangled (Greenberger-Horne-Zeilinger-)states are presented. We show the feasibility of an experimental realization in a quantum dot by the hyperfine interaction of an electron with the nuclear spins.Comment: 4+pages, 3 figure

The Warburg effect and its role in cancer detection and therapy

The Warburg effect is a cellular phenomenon in cancer cells discovered by Otto Warburg in 1924. His findings showed that in normoxic conditions tumor cells primarily use glycolysis for energy production instead of mitochondrial oxidative phosphorylation like normal cells. This breakthrough has been the basis for much research. It has resulted in a successful and widely-used cancer detection method, the positron emission tomography (PET) scan. The PET scan uses radioactive isotopes and the fact that cancer cells exhibit higher rates of glycolysis to pinpoint tumors with advanced imaging tools. Furthermore, Warburg's work helped to show the potential for beneficial pharmaceuticals that could be developed by inhibiting certain chemical mechanisms of glycolysis to specifically target and kill cancer cells. This review covers research that has used the Warburg effect as a premise and the heretofore indications and applications of the Warburg effect

Weakly Equivalent Arrays

The (extensional) theory of arrays is widely used to model systems. Hence, efficient decision procedures are needed to model check such systems. Current decision procedures for the theory of arrays saturate the read-over-write and extensionality axioms originally proposed by McCarthy. Various filters are used to limit the number of axiom instantiations while preserving completeness. We present an algorithm that lazily instantiates lemmas based on weak equivalence classes. These lemmas are easier to interpolate as they only contain existing terms. We formally define weak equivalence and show correctness of the resulting decision procedure

K→(ππ)I=2K\to(\pi\pi)_{I=2} decays and twisted boundary conditions

We propose a new method to evaluate the Lellouch-L\"uscher factor which relates the $\Delta I=3/2$ $K\to\pi\pi$ matrix elements computed on a finite lattice to the physical (infinite-volume) decay amplitudes. The method relies on the use of partially twisted boundary conditions, which allow the s-wave $\pi\pi$ phase shift to be computed as an almost continuous function of the centre-of-mass relative momentum and hence for its derivative to be evaluated. We successfully demonstrate the feasibility of the technique in an exploratory computation.Comment: 19 pages, 7 figure

Effective Quantum Dynamics of Interacting Systems with Inhomogeneous Coupling

We study the quantum dynamics of a single mode/particle interacting inhomogeneously with a large number of particles and introduce an effective approach to find the accessible Hilbert space where the dynamics takes place. Two relevant examples are given: the inhomogeneous Tavis-Cummings model (e.g., N atomic qubits coupled to a single cavity mode, or to a motional mode in trapped ions) and the inhomogeneous coupling of an electron spin to N nuclear spins in a quantum dot.Comment: 9 pages and 10 figures, new version, accepted in Physical Review

A bright, pulsed two-mode squeezer

We report the realization of a bright ultrafast two-mode squeezer based on type II parametric downconversion (PDC) in periodically poled $\mathrm{KTiOPO_4}$ (PP-KTP) waveguides. It produces a pulsed two-mode squeezed vacuum state: a photon-number entangled pair of truly single-mode pulses or, in terms of continuous variables quantum optics, a pulsed, single mode Einstein-Podolsky-Rosen (EPR) state in the telecom regime. We prove the single mode character of our source by measuring its $g^{(2)}$ correlation function and demonstrate a mean photon number of up to 2.5 per pulse, equivalent to 11dB of two-mode squeezing.Comment: 4 pages, 3 figure