Geometric Similarities and Topological Phases in Surface Magnon Polaritons.

Surface polaritons have proven to be uniquely capable of controlling light-matter interactions. Here we explore surface magnon polaritons in low-loss ferrimagnetic semiconductors, with a focus on their topological phases. We propose several surface magnon polariton devices, including microwave resonators that can strongly enhance magnetic fields and low-loss interconnects joining waveguides with vastly different impedances.

Two-qubit silicon quantum processor with operation fidelity exceeding 99.

Silicon spin qubits satisfy the necessary criteria for quantum information processing. However, a demonstration of high-fidelity state preparation and readout combined with high-fidelity single- and two-qubit gates, all of which must be present for quantum error correction, has been lacking. We use a two-qubit Si/SiGe quantum processor to demonstrate state preparation and readout with fidelity greater than 97%, combined with both single- and two-qubit control fidelities exceeding 99%.

Resonantly driven CNOT gate for electron spins.

Single-qubit rotations and two-qubit CNOT operations are crucial ingredients for universal quantum computing. Although high-fidelity single-qubit operations have been achieved using the electron spin degree of freedom, realizing a robust CNOT gate has been challenging because of rapid nuclear spin dephasing and charge noise. We demonstrate an efficient resonantly driven CNOT gate for electron spins in silicon.

All-electric control of donor nuclear spin qubits in silicon.

The electronic and nuclear spin degrees of freedom of donor impurities in silicon form ultra-coherent two-level systems that are potentially useful for applications in quantum information and are intrinsically compatible with industrial semiconductor processing. However, because of their smaller gyromagnetic ratios, nuclear spins are more difficult to manipulate than electron spins and are often considered too slow for quantum information processing. Moreover, although alternating current magnetic fields are the most natural choice to drive spin transitions and implement quantum gates, they are difficult to confine spatially to the level of a single donor, thus requiring alternative approaches.

Electron Spin Resonance at the Level of 10^{4} Spins Using Low Impedance Superconducting Resonators.

We report on electron spin resonance measurements of phosphorus donors localized in a 200  μm^{2} area below the inductive wire of a lumped element superconducting resonator. By combining quantum limited parametric amplification with a low impedance microwave resonator design, we are able to detect around 2×10^{4} spins with a signal-to-noise ratio of 1 in a single shot. The 150 Hz coupling strength between the resonator field and individual spins is significantly larger than the 1-10 Hz coupling rates obtained with typical coplanar waveguide resonator designs.

Electron Spin Coherence of Shallow Donors in Natural and Isotopically Enriched Germanium.

Germanium is a widely used material for electronic and optoelectronic devices and recently it has become an important material for spintronics and quantum computing applications. Donor spins in silicon have been shown to support very long coherence times (T_{2}) when the host material is isotopically enriched to remove any magnetic nuclei. Germanium also has nonmagnetic isotopes so it is expected to support long T_{2}'s while offering some new properties.

Anisotropic stark effect and electric-field noise suppression for phosphorus donor qubits in silicon.

We report the use of novel, capacitively terminated coplanar waveguide resonators to measure the quadratic Stark shift of phosphorus donor qubits in Si. We confirm that valley repopulation leads to an anisotropic spin-orbit Stark shift depending on electric and magnetic field orientations relative to the Si crystal. By measuring the linear Stark effect, we estimate the effective electric field due to strain in our samples.

Acute afferent loop obstruction treated by endoscopic decompression. Case report and review of literature.

Afferent loop syndrome (ALS) is a rare complication of Billroth-II gastrojejunostomy. Most cases of ALS are caused by obstruction from adhesions, kinking at the anastomosis, internal hernia, stomal stenosis, malignancy, or inflammation surrounding the anastomosis. A 61-years old man, who had undergone gastric resection 30 years before, was admitted at emergency room with severe abdominal pain in acute onset, nausea and vomiting.

Screening for colorectal cancer in Italy: 2005 survey.

We present the main results from the second survey of the Italian screening programmes for colorectal cancer carried out by the National Centre for Screening Monitoring on behalf of the Ministry of Health. During 2005, 52 programmes, adopting faecal occult blood testing (FOBT), sigmoidoscopy (FS), or a combination of both, were active in Italy. Overall, 827,473 subjects were invited to FOBT and 376,240 were screened; the adjusted attendance rate (47.

Gabexate or somatostatin administration before ERCP in patients at high risk for post-ERCP pancreatitis: a multicenter, placebo-controlled, randomized clinical trial.

Background: ERCP is frequently complicated by pancreatitis. The aims of this study were to assess the efficacy of somatostatin and gabexate for prevention of post-ERCP pancreatitis in high-risk patients and to determine predisposing factors for post-ERCP pancreatitis. A meta-analysis was conducted of all published studies on the use of somatostatin or gabexate for prevention of post-ERCP pancreatitis.