Optical signatures of silicon-vacancy spins in diamond

Colour centres in diamond have emerged as versatile tools for solid-state quantum technologies ranging from quantum information to metrology, where the nitrogen-vacancy centre is the most studied to date. Recently, this toolbox has expanded to include novel colour centres to realize more efficient spin-photon quantum interfaces. Of these, the silicon-vacancy centre stands out with highly desirable photonic properties. The challenge for utilizing this centre is to realize the hitherto elusive optical access to its electronic spin. Here we report spin-tagged resonance fluorescence from the negatively charged silicon-vacancy centre. Our measurements reveal a spin-state purity approaching unity in the excited state, highlighting the potential of the centre as an efficient spin-photon quantum interface

Rapid investigation of nanocrystalline diamond vibrating membranes with a stroboscopic interferometer

Nanocrystalline diamond is a promising material for the fabrication of highly sensitive flexural plate wave (FPW) sensors. The design of the FPW sensor requires the determination of the mechanical properties of a thin film membrane. In this paper we investigate the mechanical resonance of nanocrystalline diamond membranes with a stroboscopic interferometer optical system. Membranes with lateral dimensions in the range 0.8 to 6 mm and about 1 mu m thick were excited in air by a loudspeaker. The resonance frequencies helped to determine the mechanical properties of the diamond membrane and give directly the parameter of interest for the FPW sensor design. Our method allows the rapid investigation of the material without requiring an integrated transduction system and can be used to analyze structures with the actual dimensions of the FPW sensor.Anglai

Chemical Basis of Interactions Between Engineered Nanoparticles and Biological Systems

A recently reported incident of severe pulmonary fibrosis caused by inhaled polymer nanoparticles in seven female workers obtained much attention. In addition to the release of ENM waste from industrial sites, a major release of ENMs to environmental water occurs due to home and personal use of appliances, cosmetics, and personal products, such as shampoo and sunscreen. Airborne and aqueous ENMs pose immediate danger to the human respiratory and gastrointestinal systems. ENMs may enter other human organs after they are absorbed into the bloodstream through the gastrointestinal and respiratory systems. Practically, a thorough understanding of the fundamental chemical interactions between nanoparticles and biological systems has two direct impacts. First, this knowledge will encourage and assist experimental approaches to chemically modify nanoparticle surfaces for various industrial or medicinal applications