1,369 research outputs found
Nanoscale magnetometry through quantum control of nitrogen-vacancy centres in rotationally diffusing nanodiamonds
The confluence of quantum physics and biology is driving a new generation of
quantum-based sensing and imaging technology capable of harnessing the power of
quantum effects to provide tools to understand the fundamental processes of
life. One of the most promising systems in this area is the nitrogen-vacancy
centre in diamond - a natural spin qubit which remarkably has all the right
attributes for nanoscale sensing in ambient biological conditions. Typically
the nitrogen-vacancy qubits are fixed in tightly controlled/isolated
experimental conditions. In this work quantum control principles of
nitrogen-vacancy magnetometry are developed for a randomly diffusing diamond
nanocrystal. We find that the accumulation of geometric phases, due to the
rotation of the nanodiamond plays a crucial role in the application of a
diffusing nanodiamond as a bio-label and magnetometer. Specifically, we show
that a freely diffusing nanodiamond can offer real-time information about local
magnetic fields and its own rotational behaviour, beyond continuous optically
detected magnetic resonance monitoring, in parallel with operation as a
fluorescent biomarker.Comment: 9 pages, with 5 figure
SESAME: exploring small businesses' behaviour to enhance resilience to flooding
In the United Kingdom, small and medium sized enterprises (SMEs) account for approximately 99.9% of businesses, 60% of the working population and 47% annual turnover. However, despite the important contribution that SMEs make to the economy, this size of business remains under-researched with a significant gap in understanding how the disruption caused by flooding impacts on SMEs from the time at which a flood event occurs through to the 'return' to normal operations. Business continuity management is a recognised approach for enhancing organisational resilience to major disruptions (ISO 22301, 2012). However, this strategic approach to building such resilience in SMEs is under-explored in the literature with a limited range of empirical data to draw on. This paper presents an overview of an inter-disciplinary research project funded by the UK's Engineering and Physical Science Research Council, called SESAME, which examines SMEs' operational response and preparedness to flooding. Furthermore, SESAME consists of four stands of research which bring together a number of disciplines including agent based modelling and simulation, flood modelling, business continuity management, economic modelling and behavioural science. This paper provides an overview of the different research stands within the SESAME project aimed at enhancing SMEs' resilience to flooding
Helping education undergraduates to use appropriate criteria for evaluating accounts of motivation
The aim of the study was to compare students in a control group with those in a treatment group with respect to evaluative comments on psychological accounts of motivation. The treatment group systematically scrutinized the nature and interpretation of evidence that supported different accounts, and the assumptions, logic, coherence and clarity of accounts. Content analysis of 74 scripts (using three categories) showed that the control group students made more assertions than either evidential or evaluative points, whereas the treatment group used evaluative statements as often as they used assertion. The findings provide support for privileging activities that develop understanding of how knowledge might be contested, and suggest a need for further research on pedagogies to serve this end. The idea is considered that such understanding has a pivotal role in the development of critical thinking
The devices, experimental scaffolds, and biomaterials ontology (DEB): a tool for mapping, annotation, and analysis of biomaterials' data
The size and complexity of the biomaterials literature makes systematic data analysis an excruciating manual task. A practical solution is creating databases and information resources. Implant design and biomaterials research can greatly benefit from an open database for systematic data retrieval. Ontologies are pivotal to knowledge base creation, serving to represent and organize domain knowledge. To name but two examples, GO, the gene ontology, and CheBI, Chemical Entities of Biological Interest ontology and their associated databases are central resources to their respective research communities. The creation of the devices, experimental scaffolds, and biomaterials ontology (DEB), an open resource for organizing information about biomaterials, their design, manufacture, and biological testing, is described. It is developed using text analysis for identifying ontology terms from a biomaterials gold standard corpus, systematically curated to represent the domain's lexicon. Topics covered are validated by members of the biomaterials research community. The ontology may be used for searching terms, performing annotations for machine learning applications, standardized meta-data indexing, and other cross-disciplinary data exploitation. The input of the biomaterials community to this effort to create data-driven open-access research tools is encouraged and welcomed.Preprin
Constructing Conceptual Knowledge Artefacts: Activity Patterns in the Ontology Authoring Process
Long-lived driven solid-state quantum memory
We investigate the performance of inhomogeneously broadened spin ensembles as
quantum memories under continuous dynamical decoupling. The role of the
continuous driving field is two-fold: first, it decouples individual spins from
magnetic noise; second and more important, it suppresses and reshapes the
spectral inhomogeneity of spin ensembles. We show that a continuous driving
field, which itself may also be inhomogeneous over the ensemble, can enhance
the decay of the tails of the inhomogeneous broadening distribution
considerably. This fact enables a spin ensemble based quantum memory to exploit
the effect of cavity protection and achieve a much longer storage time. In
particular, for a spin ensemble with a Lorentzian spectral distribution, our
calculations demonstrate that continuous dynamical decoupling has the potential
to improve its storage time by orders of magnitude for the state-of-art
experimental parameters
Integrated optical addressing of a trapped ytterbium ion
We report on the characterization of heating rates and photo-induced electric
charging on a microfabricated surface ion trap with integrated waveguides.
Microfabricated surface ion traps have received considerable attention as a
quantum information platform due to their scalability and manufacturability.
Here we characterize the delivery of 435 nm light through waveguides and
diffractive couplers to a single ytterbium ion in a compact trap. We measure an
axial heating rate at room temperature of q/ms and see no
increase due to the presence of the waveguide. Furthermore, the electric field
due to charging of the exposed dielectric outcoupler settles under normal
operation after an initial shift. The frequency instability after settling is
measured to be 0.9 kHz.Comment: 7 pages, 8 figure
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