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Entanglement—one of the most delicate phenomena in nature—is an essential resource for quantum information applications. Scalable photonic quantum devices must generate and control qubit entanglement on-chip, where quantum information is naturally encoded in photon path. Here we report a silicon photonic chip that uses resonant-enhanced photon-pair sources, spectral demultiplexers and reconfigurable optics to generate a path-entangled two-qubit state and analyse its entanglement. We show that ring-resonator-based spontaneous four-wave mixing photon-pair sources can be made highly indistinguishable and that their spectral correlations are small. We use on-chip frequency demultiplexers and reconfigurable optics to perform both quantum state tomography and the strict Bell-CHSH test, both of which confirm a high level of on-chip entanglement. This work demonstrates the integration of high-performance components that will be essential for building quantum devices and systems to harness photonic entanglement on the large scale. Scalable photonic devices for quantum information processing require on-chip quantum states engineering. Here the authors report the creation of entangled photon pairs on a silicon-on-insulator chip by integrating resonant photon sources, spectral demultiplexers and reconfigurable optics in a single device.

Fully etched photonic wires in silicon-on-insulator have been fabricated and propagation loss values as low as 0.92+/-0.14dB/cm have been obtained. Hydrogen silsesquioxane (HSQ) was used as an electron beam resist and as a direct mask in the dry-etch processing of the silicon core layer. The dimensional repeatability of the fabrication process was also estimated through measurements of the wavelength selection performance of nominally identical photonic wire Bragg gratings fabricated at intervals over a period of 37 days.

Recent results and status from the HARP and MIPP hadron production experiments are reviewed. After a brief description of the experimental setups and the large amounts of data collected with those, we emphasize the relevance of precision hadron production measurements for neutrino physics. Three types of neutrino sources are discussed: conventional accelerator-based neutrino beams, advanced neutrino sources, and atmospheric neutrinos. We conclude by discussing prospects from additional hadron production measurements to be expected in the near future.

MiniBooNE's first results on a search for an electron neutrino excess in a muon neutrino beam are presented, together with an analysis of the data within a two neutrino Vμ → Ve appearance-only oscillation context. MiniBooNE finds excellent agreement between data and Standard Model predictions in the oscillation analysis energy region. If neutrino and antineutrino oscillations are the same, MiniBooNE excludes at ∼98% confidence level the two neutrino Vμ → Ve appearance-only oscillation interpretation of the LSND anomaly. MiniBooNE also finds a discrepancy at energies below the oscillation analysis range, which is currently not understood and under investigation.

The physics motivations, design, and status of the Booster Neutrino Experiment at Fermilab, MiniBooNE, are briefly discussed. Particular emphasis is given on the ongoing preparatory work that is needed for the MiniBooNE muon neutrino to electron neutrino oscillation appearance search. This search aims to confirm or refute in a definitive and independent way the evidence for neutrino oscillations reported by the LSND experiment.

A bstract The Neutrino Experiment with a Xenon TPC (NEXT) searches for the neutrinoless double-beta (0 νββ ) decay of 136 Xe using high-pressure xenon gas TPCs with electroluminescent amplification. A scaled-up version of this technology with about 1 tonne of enriched xenon could reach in less than 5 years of operation a sensitivity to the half-life of 0 νββ decay better than 10 27 years, improving the current limits by at least one order of magnitude. This prediction is based on a well-understood background model dominated by radiogenic sources. The detector concept presented here represents a first step on a compelling path towards sensitivity to the parameter space defined by the inverted ordering of neutrino masses, and beyond.

To determine the relationship between diagnosed and treated COPD and the incidence of cardiovascular disease (CVD) hospitalization and mortality. Retrospective matched cohort study. Northern California Kaiser Permanente Medical Care Program (KPNC), a comprehensive prepaid integrated health-care system. Case patients (n = 45,966) were all KPNC members with COPD who were identified during a 4-year period from January 1996 through December 1999. An equal number of control subjects without COPD were selected from KPNC membership and were matched for gender, year of birth, and length of KPNC membership. Follow-up conducted for hospitalization and mortality from CVD end points through December 31, 2000. CVD study end points included cardiac arrhythmias, angina pectoris, acute myocardial infarction, congestive heart failure (CHF), stroke, pulmonary embolism, all of the aforementioned study end points combined, other CVD, and all CVD end points. The mean follow-up time was 2.75 years for case patients and 2.99 years for control subjects. The risk of hospitalization was higher in COPD case patients than in control subjects for all CVD hospitalization and mortality end points. The relative risk (RR) for hospitalization for the composite measure of all study end points was 2.09 (95% confidence interval [CI], 1.99 to 2.20) after adjustment for gender, preexisting CVD study end points, hypertension, hyperlipidemia, and diabetes, and ranged from 1.33 (stroke) to 3.75 (CHF). The adjusted RR for mortality for the composite measure of all study end points was 1.68 (95% CI, 1.50 to 1.88), ranging from 1.25 (stroke) to 3.53 (CHF). Younger patients (ie, age < 65 years) and female patients had higher risks than older and male participants. COPD was a predictor of CVD hospitalization and mortality over an average follow-up time of nearly 3 years. The finding of a stronger relationship of COPD to CVD outcomes in patients < 65 years of age suggests that CVD risk should be monitored and treated with particular care in younger adults with COPD.

In the last few years, transcranial direct current stimulation (tDCS) has emerged as an appealing therapeutic option to improve brain functions. Promising data support the role of prefrontal tDCS in augmenting cognitive performance and ameliorating several neuropsychiatric symptoms, namely pain, fatigue, mood disturbances, and attentional impairment. Such symptoms are commonly encountered in patients with multiple sclerosis (MS). The main objective of the current work was to evaluate the tDCS effects over the left dorsolateral prefrontal cortex (DLPFC) on pain in MS patients.Our secondary outcomes were to study its influence on attention, fatigue, and mood. Sixteen MS patients with chronic neuropathic pain were enrolled in a randomized, sham-controlled, and cross-over study.Patients randomly received two anodal tDCS blocks (active or sham), each consisting of three consecutive daily tDCS sessions, and held apart by 3 weeks. Evaluations took place before and after each block. To evaluate pain, we used the Brief Pain Inventory (BPI) and the Visual Analog Scale (VAS). Attention was assessed using neurophysiological parameters and the Attention Network Test (ANT). Changes in mood and fatigue were measured using various scales. Compared to sham, active tDCS yielded significant analgesic effects according to VAS and BPI global scales.There were no effects of any block on mood, fatigue, or attention. Based on our results, anodal tDCS over the left DLPFC appears to act in a selective manner and would ameliorate specific symptoms, particularly neuropathic pain. Analgesia might have occurred through the modulation of the emotional pain network. Attention, mood, and fatigue were not improved in this work. This could be partly attributed to the short protocol duration, the small sample size, and the heterogeneity of our MS cohort. Future large-scale studies can benefit from comparing the tDCS effects over different cortical sites, changing the stimulation montage, prolonging the duration of protocol, and coupling tDCS with neuroimaging techniques for a better understanding of its possible mechanism of action.