Absorption and birefringence study for reduced optical losses in diamond with high NV concentration

The use of diamond color centers such as the nitrogen-vacancy (NV) center is increasingly enabling quantum sensing and computing applications. Novel concepts like cavity coupling and readout, laser threshold magnetometry and multi-pass geometries allow significantly improved sensitivity and performance via increased signals and strong light fields. Enabling material properties for these techniques and their further improvements are low optical material losses via optical absorption of signal light and low birefringence. Here we study systematically the behavior of absorption around 700 nm and birefringence with increasing nitrogen- and NV-doping, as well as their behavior during NV creation via diamond growth, electron beam irradiation and annealing treatments. Absorption correlates with increased nitrogen-doping yet substitutional nitrogen does not seem to be the direct absorber. Birefringence reduces with increasing nitrogen doping. We identify multiple crystal defect concentrations via absorption spectroscopy and their changes during the material processing steps and thus identify potential causes of absorption and birefringence as well as strategies to fabricate CVD diamonds with high NV density yet low absorption and low birefringence.Comment: Accepted by Philosophical Transactions A (DOI: 10.1098/rsta.2022.0314

Feedbacks of plant identity and diversity on the diversity and community composition of rhizosphere microbiomes from a long-term biodiversity experiment

Soil microbes are known to be key drivers of several essential ecosystem processes such as nutrient cycling, plant productivity and the maintenance of plant species diversity. However, how plant species diversity and identity affect soil microbial diversity and community composition in the rhizosphere is largely unknown. We tested whether, over the course of 11 years, distinct soil bacterial communities developed under plant monocultures and mixtures, and if over this time frame plants with a monoculture or mixture history changed in the bacterial communities they associated with. For eight species, we grew offspring of plants that had been grown for 11 years in the same field monocultures or mixtures (plant history in monoculture vs. mixture) in pots inoculated with microbes extracted from the field monoculture and mixture soils attached to the roots of the host plants (soil legacy). After 5 months of growth in the glasshouse, we collected rhizosphere soil from each plant and used 16S rRNA gene sequencing to determine the community composition and diversity of the bacterial communities. Bacterial community structure in the plant rhizosphere was primarily determined by soil legacy and by plant species identity, but not by plant history. In seven of the eight plant species the number of individual operational taxonomic units with increased abundance was larger when inoculated with microbes from mixture soil. We conclude that plant species richness can affect below-ground community composition and diversity, feeding back to the assemblage of rhizosphere bacterial communities in newly establishing plants via the legacy in soil.</p

Creating Space in the Catholic Church for Same Sex Parents

The Catholic Church holds that same sex parents do violence to their children as these parental relationships lack two fundamental qualities: the ability to procreate and complementarity. In spite of the Church’s negative view on same sex parenting, its position is flawed as there are significant gaps in the Church’s arguments against same sex parents. By looking more deeply at the Church’s teachings and by considering the progress society has made in its understanding of same sex parents, the Church should reconsider its position, creating a more inclusive church body

Authenticity-Based Connections as Organizational Constraints and the Paradox of Authenticity in the Market for Cuban Cigars

We explore the organizational consequences that different authenticity claims carry for products and the firms that produce them. To do so we build on the notion of an authenticity paradox – the idea that seeking to capture demand that is created by perceived authenticity can undermine the very authenticity that generated the demand in the first place. Using an experimental approach, we argue and show that provenance-based claims of authenticity (e.g., location of origin) constrain a firm spaciotemporally, limiting their ability to expand production in ways that might be economically rational, but would undermine this authenticity claim. We further show that such an action is not penalized (or penalized less) when the basis of the claim is not spacio-temporally linked and is instead based on more diffuse associations with an iconic image but is also associated with a place. We show how these types of connections help firms respond to the authenticity paradox by allowing them more freedom to expand production to meet the increased demand without undermining the original claims to authenticity. As a result, this paper’s key contribution lies in moving beyond explaining how perceived authenticity benefits organizations, and instead explores how different claims to authenticity can constrain a firm’s ability to capture the value they have created from authenticity