Classical clock synchronization for quantum communications using the quantum channel.

We present a time synchronization method for correlation of photon arrival times for quantum communication. The method employs a low-power, low-frequency synchronization beacon that shares the quantum channel and is detected using the same single-photon detectors already present in the quantum communication system. We show experimentally that the system jitter approaches the system resolution limit with negligible impact on the quantum channel in realistic use cases.

Enhancing SPDC brightness using elliptical pump shapes.

We report on the use of elliptical pump spatial modes to increase the observed brightness of spontaneous parametric downconversion in critically phase-matched crystals. Simulations qualitatively predict this improvement, which depends on the eccentricity and orientation of the pump ellipse. We experimentally confirm a factor of two improvement in brightness when compared to the traditional circular-symmetric pump spatial modes.

Manipulation and measurement of quantum states with liquid crystal devices.

We present the use of liquid crystal retarders (LCR) as phase control elements in optical quantum technologies. We show that an entangled photon pair state can be actively controlled using an LCR without introducing state mixing or polarization drifts. Similarly, we demonstrate that the entanglement quality can be conveniently analyzed using liquid crystal polarization retarders.

Experimental entangled photon pair generation using crystals with parallel optical axes.

We present an optical design where polarization-entangled photon pairs are generated within two β-Barium Borate crystals whose optical axes are parallel. This design increases the spatial mode overlap of the emitted photon pairs enhancing single mode collection without the need for additional spatial walk-off compensators. The observed photon pair rate is at least 65 000 pairs/s/mW with a quantum state fidelity of 99.

Fluorescent color centers in laser ablated 4H-SiC nanoparticles.

Nanostructured and bulk silicon carbide (SiC) has recently emerged as a novel platform for quantum nanophotonics due to its harboring of paramagnetic color centers, having immediate applications as a single photon source and spin optical probes. Here, using ultra-short pulsed laser ablation, we fabricated from electron irradiated bulk 4H-SiC, 40-50 nm diameter SiC nanoparticles, fluorescent at 850-950 nm. This photoluminescence is attributed to the silicon vacancy color centers.

A review on single photon sources in silicon carbide.

This paper summarizes key findings in single-photon generation from deep level defects in silicon carbide (SiC) and highlights the significance of these individually addressable centers for emerging quantum applications. Single photon emission from various defect centers in both bulk and nanostructured SiC are discussed as well as their formation and possible integration into optical and electrical devices. The related measurement protocols, the building blocks of quantum communication and computation network architectures in solid state systems, are also summarized.

Diamond encapsulated photovoltaics for transdermal power delivery.

A safe, compact and robust means of wireless energy transfer across the skin barrier is a key requirement for implantable electronic devices. One possible approach is photovoltaic (PV) energy delivery using optical illumination at near infrared (NIR) wavelengths, to which the skin is highly transparent. In the work presented here, a subcutaneously implantable silicon PV cell, operated in conjunction with an external NIR laser diode, is developed as a power delivery system.

Single-photon emitting diode in silicon carbide.

Electrically driven single-photon emitting devices have immediate applications in quantum cryptography, quantum computation and single-photon metrology. Mature device fabrication protocols and the recent observations of single defect systems with quantum functionalities make silicon carbide an ideal material to build such devices. Here, we demonstrate the fabrication of bright single-photon emitting diodes.

Ultra-high-density 3D DNA arrays within nanoporous biocompatible membranes for single-molecule-level detection and purification of circulating nucleic acids.

Extracellular nucleic acids freely circulating in blood and other physiologic fluids are important biomarkers for non-invasive diagnostics and early detection of cancer and other diseases, yet difficult to detect because they exist in very low concentrations and large volumes. Here we demonstrate a new broad-range sensor platform for ultrasensitive and selective detection of circulating DNA down to the single-molecule level. The biosensor is based on a chemically functionalized nanoporous diamond-like carbon (DLC) coated alumina membrane.

Fabrication of planarised conductively patterned diamond for bio-applications.

The development of smooth, featureless surfaces for biomedical microelectronics is a challenging feat. Other than the traditional electronic materials like silicon, few microelectronic circuits can be produced with conductive features without compromising the surface topography and/or biocompatibility. Diamond is fast becoming a highly sought after biomaterial for electrical stimulation, however, its inherent surface roughness introduced by the growth process limits its applications in electronic circuitry.

Pre-winter lipid stores in young-of-year Atlantic salmon along a north-south gradient.

The pre-winter lipid stores of young-of-the-year (YOY, age 0 year) Atlantic salmon Salmo salar were analysed along a north-south gradient from c. 71 to 58 degrees N, with winter conditions ranging from >200 days of ice cover to no ice. The rivers sampled in Northern Norway represent some of the most northerly S.

[Multiple endocrine adenopathy type IIb. 15-years' observation of a case].

MEA IIb is a combination of C-cell carcinoma of the thyroid, phaeochromocytoma, multiple neuromas and a marfanoid habitus. A hyperplasia of the parathyroid cannot be found in most of the patients with this variant of Sipple's syndrome. In a 30-year-old woman, a MEA IIb could be observed over 15 years.

[Neurofibroma of the small bowel in Recklinghausen's disease as a rare cause of chronic intestinal bleeding (author's transl)].

A case report is given of a 66 year old woman with Recklinghausen's disease, suffering from chronic gastrointestinal bleeding as a rare complication of enteric neurofibromatosis. Localization could be established only by angiography. After resection of the tumor with an ulceration at its tip hemorrhage stopped.

[Immunsuppressive factors in sera and synovial fluids of patients with rheumatoid arthritis (author's transl)].

Serum inhibitory factors (SIF) have been demonstrated in several infectious diseases and autoimmune disorders. Most likely, they are caused by an immune reaction, and their persistence indicates a chronic course. Sera and synovial fluids of 31 patients with rheumatoid arthritis and of 33 patients with arthrosis were therefore studied, in order to determine whether immunosuppressive factors exist only in inflammatory diseases and whether their titers correlate with the activity of the disease.