Identification and tunable optical coherent control of transition-metal spins in silicon carbide

Color centers in wide-bandgap semiconductors are attractive systems for quantum technologies since they can combine long-coherent electronic spin and bright optical properties. Several suitable centers have been identified, most famously the nitrogen-vacancy defect in diamond. However, integration in communication technology is hindered by the fact that their optical transitions lie outside telecom wavelength bands. Several transition-metal impurities in silicon carbide do emit at and near telecom wavelengths, but knowledge about their spin and optical properties is incomplete. We present all-optical identification and coherent control of molybdenum-impurity spins in silicon carbide with transitions at near-infrared wavelengths. Our results identify spin $S=1/2$ for both the electronic ground and excited state, with highly anisotropic spin properties that we apply for implementing optical control of ground-state spin coherence. Our results show optical lifetimes of $\sim$60 ns and inhomogeneous spin dephasing times of $\sim$0.3 $\mu$s, establishing relevance for quantum spin-photon interfacing.Comment: Updated version with minor correction, full Supplementary Information include

Divertor conditions relevant for fusion reactors achieved with linear plasma generator

Intense magnetized hydrogen and deuterium plasmas have been produced with electron densities up to 3.6¿×¿1020¿m-3 and electron temperatures up to 3.7¿eV with a linear plasma generator. Exposure of a W target has led to average heat and particle flux densities well in excess of 4¿MW m-2 and 1024¿m-2 s-1, respectively. We have shown that the plasma surface interactions are dominated by the incoming ions. The achieved conditions correspond very well to the projected conditions at the divertor strike zones of fusion reactors such as ITER. In addition, the machine has an unprecedented high gas efficiency

Incidence and impact of postoperative pancreatic fistula after minimally invasive and open distal pancreatectomy

BACKGROUND: Previous studies reported a higher rate of postoperative pancreatic fistula after minimally invasive distal pancreatectomy compared to open distal pancreatectomy. It is unknown whether the clinical impact of postoperative pancreatic fistula after minimally invasive distal pancreatectomy is comparable with that after open distal pancreatectomy. We aimed to compare not only the incidence of postoperative pancreatic fistula, but more importantly, also its clinical impact. METHODS: This is a post hoc analysis of a multicenter randomized trial investigating a possible beneficial impact of a fibrin patch on the rate of clinically relevant postoperative pancreatic fistula (International Study Group for Pancreatic Surgery grade B/C) after distal pancreatectomy. Primary outcomes of the current analysis are the incidence and clinical impact of postoperative pancreatic fistula after both minimally invasive distal pancreatectomy and open distal pancreatectomy. RESULTS: From October 2010 to August 2017, 252 patients undergoing distal pancreatectomy were randomized, and data of 247 patients were available for analysis: 87 minimally invasive distal pancreatectomy and 160 open distal pancreatectomies. The postoperative pancreatic fistula rate after minimally invasive distal pancreatectomy was significantly higher than that after open distal pancreatectomy (28.7% vs 16.9%, P = .029). More patients were discharged with an abdominal surgical drain after minimally invasive distal pancreatectomy compared to open distal pancreatectomy (30/87, 34.5% vs 26/160, 16.5%, P = .001). In patients with postoperative pancreatic fistula, additional percutaneous catheter drainage procedures were performed less often (52% vs 84.6%, P = .012), with fewer drainage procedures (median [range], 2 [1-4] vs 2, [1-7], P = .014) after minimally invasive distal pancreatectomy. CONCLUSION: In this post hoc analysis, the postoperative pancreatic fistula rate after minimally invasive distal pancreatectomy was higher than that after open distal pancreatectomy, whereas the clinical impact was less

High heat flux capabilities of the Magnum-PSI linear plasma device

Magnum-PSI is an advanced linear plasma device uniquely capable of producing plasma conditions similar to those expected in the divertor of ITER both steady-state and transients. The machine is designed both for fundamental studies of plasma-surface interactions under high heat and particle fluxes, and as a high-heat flux facility for the tests of plasma-facing components under realistic plasma conditions. To study the effects of transient heat loads on a plasma-facing surface, a novel pulsed plasma source system as well as a high power laser is available. In this article, we will describe the capabilities of Magnum-PSI for high-heat flux tests of plasma-facing material

Healthy aging and disease: role for telomere biology?

Aging is a biological process that affects most cells, organisms and species. Human aging is associated with increased susceptibility to a variety of chronic diseases, including cardiovascular disease, Type 2 diabetes, neurological diseases and cancer. Despite the remarkable progress made during the last two decades, our understanding of the biology of aging remains incomplete. Telomere biology has recently emerged as an important player in the aging and disease process

New linear plasma devices in the trilateral euregio cluster for an integrated approach to plasma surface interactions in fusion reactors

New linear plasma devices are currently being constructed or planned in the Trilateral Euregio Cluster (TEC) to meet the challenges with respect to plasma surface interactions in DEMO and ITER: i) MAGNUM-PSI (FOM), a high particle and power flux device with super-conducting magnetic field coils which will reach ITER-like divertor conditions at high magnetic field, ii) the newly proposed linear plasma device JULE-PSI (FZJ), which will allow to expose toxic and neutron activated target samples to ITER-like fluences and ion energies including in vacuo analysis of neutron activated samples, and iii) the plasmatron VISION I. a compact plasma device which will be operated inside the tritium lab at SCK-CEN Mol, capable to investigate tritium plasmas and moderately activated wall materials. This contribution shows the capabilities of the new devices and their forerunner experiments (Pilot-PSI at FOM and PSI-2 Julich at FZJ) in view of the main objectives of the new TEC program on plasma surface interactions. (C) 2011 Forschungszentrum Julich, Institut fur Energieforschung-Plasmaphysik. Published by Elsevier B.V. All rights reserved