Fermionic Atoms in Optical Superlattices

Fermionic atoms in an optical superlattice can realize a very peculiar Anderson lattice model in which impurities interact with each other through a discretized set of delocalized levels. We investigate the interplay between Kondo effect and magnetism under these finite-size features. We find that Kondo effect can dominate over magnetism depending on the parity of the number of particles per discretized set. We show how Kondo-induced resonances of measurable size can be observed through the atomic interference pattern

All-optical non-demolition measurement of single-hole spin in a quantum-dot molecule

We propose an all-optical scheme to perform a non-demolition measurement of a single hole spin localized in a quantum-dot molecule. The latter is embedded in a microcavity and driven by two lasers. This allows to induce Raman transitions which entangle the spin state with the polarization of the emitted photons. We find that the measurement can be completed with high fidelity on a timescale of 100 ps, shorter than the typical T2. Furthermore, we show that the scheme can be used to induce and observe spin oscillations without the need of time-dependent magnetic fields

Optimizing photon indistinguishability in the emission from incoherently-excited semiconductor quantum dots

Most optical quantum devices require deterministic single-photon emitters. Schemes so far demonstrated in the solid state imply an energy relaxation which tends to spoil the coherent nature of the time evolution, and with it the photon indistinguishability. We focus our theoretical investigation on semiconductor quantum dots embedded in microcavities. Simple and general relations are identified between the photon indistinguishability and the collection efficiency. The identification of the key parameters and of their interplay provides clear indications for the device optimization

Polarization entanglement visibility of photon pairs emitted by a quantum dot embedded in a microcavity

We study the photon emission from a quantum dot embedded in a microcavity. Incoherent pumping of its excitons and biexciton provokes the emission of leaky and cavity modes. By solving a master equation we obtain the correlation functions required to compute the spectrum and the relative efficiency among the emission of pairs and single photons. A quantum regime appears for low pumping and large rate of emission. By means of a post-selection process, a two beams experiment with different linear polarizations could be performed producing a large polarization entanglement visibility precisely in the quantum regime.Comment: 13 pages and 6 figure

Cost-effectiveness analysis of tropisetron vs. chlorpromazine-dexamethasone in the control of acute emesis induced by highly emetogenic chemotherapy in children

To perform a cost-effectiveness analysis (CEA) between a standard antiemetic regimen-chlorpromazine + dexamethasone (CPM-DEX)- and a 5-HT3 receptor antagonist-tropisetron (TROP)--in the control of acute emesis induced by highly emetogenic chemotherapy in children, considering two analytic perspectives: hospital and patients. METHODS: The CEA was performed by constructing a decision tree, for both analytic perspectives, of the possible outcomes of treatment with TROP (single 0.2 mg/kg i.v.) or CPM (5-15 mg i.v. infusion for 3 doses) plus DEX (2 mg/m2 i.v. bolus i.v. x2). The patients were stratified by age in two groups (2-12 and 13-17). To estimate the probability of each endpoint at the decision tree we have taken as a base a trial developed in the Department of Pediatrics. Direct medical cost of primary therapy, failure, complications and side effects were included in the cost calculations. RESULTS: From patients' analytic perspective, TROP was more cost-effective than CPM-DEX for both groups of patients. Discrepancy between both analytic perspectives in 13-17 year-old patient's group was resolved in favour of the option chosen from the patients' analytic perspective (TROP). Sensitivity analysis showed the reliability of the results. CONCLUSIONS: 1. TROP was more cost-effective than CPM-DEX. 2. Taking into account the patients' analytic perspective is essential when we compare antiemetics pharmacoeconomically. 3. It seems necessary to increase the effectiveness of TROP in pediatric patients receiving highly emetogenic chemotherapy with strategies such as the addition of a steroid