ABSTRACT
Diamond's nitrogen vacancy (NV) center is an optically active defect with long spin coherence times, showing great potential for both efficient nanoscale magnetometry and quantum information processing schemes. Recently, both the formation of buried 3D optical waveguides and high-quality single NVs in diamond were demonstrated using the versatile femtosecond laser-writing technique. However, until now, combining these technologies has been an outstanding challenge. In this Letter, we fabricate laser-written photonic waveguides in quantum grade diamond which are aligned to within micron resolution to single laser-written NVs, enabling an integrated platform providing deterministically positioned waveguide-coupled NVs. This fabrication technology opens the way toward on-chip optical routing of single photons between NVs and optically integrated spin-based sensing.
ABSTRACT
Ionic glasses obtained combining silver iodide and silver molybdate are characterized by quite low values of the glass transition temperature T(g) around 320-350 K, by high values of the dc ionic conductivity even at room temperature and by a peculiar behavior of the mechanical response at ultrasonic frequencies. In fact, at temperatures well below their glass transition temperature, these glasses exhibit an intense peak of acoustic attenuation well described by two different and almost overlapping relaxational contributions. Considering also that negative thermal expansion has been reported for some molybdate crystalline compounds, we have investigated in this work the thermal expansion of two silver iodomolybdate glasses (AgI)(1-x)(Ag(2)MoO(4))(x) for x=0.25 and x=0.33 in a wide temperature range (4.2-300 K) from cryogenic temperatures up to some 20 K below T(g) using a precision capacitance dilatometer aiming to understand whether the expansivity shows some possible fingerprint corresponding to the above-mentioned mechanical response. Two different measuring methods, a quasiadiabatic and a continuous one, have been used for the thermal expansion measurements. The results are discussed in comparison with the information obtained from previous investigations based on the extended x-ray absorption fine structure (EXAFS) technique and with the behavior of other ionic glasses.
ABSTRACT
A large number of AgI-based fast-ion-conducting glasses have been investigated by K-iodine extended x-ray absorption fine structure spectroscopy (EXAFS) measurements at liquid nitrogen temperature. A general correlation between the I-Ag distance measured by EXAFS and the glass activation energy for dc ionic conductivity has been found out: glasses with longer I-Ag distances display higher ionic conductivity, independently from the chemical composition of their host glassy matrix. This behavior can be related to the progressive increase of the "pathway volume" for ionic conduction.
ABSTRACT
From January, 1972, until August, 1980, 271 manual coronary endarterectomies with bypass were performed in 263 patients. All patients underwent additional cardiac procedures simultaneously. The group contained 254 distal right and 17 left endarterectomies (including 8 double endarterectomies). Clinical follow-up was 100%, operative mortality was 2.3% (6 out of 263), and the rate of perioperative infarction was 4.9% (13 out of 263). Cineangiography was performed on 72 patients between 1 and 60 months after operation (mean, 15.4 months). Patency was 85% (61 out of 72). Endarterectomy in a dominant right coronary artery could be planned electively. Left coronary endarterectomy was performed only when diffuse disease prevented standard bypass. Coronary endarterectomy may be used to extend operability with excellent clinical results, low perioperative mortality, and high late patency. Careful attention to technical aspects of core removal and myocardial protection are necessary for consistent results.