5 research outputs found
Tip-enhanced strong coupling spectroscopy and control of a single quantum emitter
No full textOptical cavities can enhance and control light-matter interactions. This has recently
been extended to the nanoscale, and with single emitter strong coupling
regime even at room temperature using plasmonic nano-cavities with deep
sub-diffraction-limited mode volumes. However, with emitters in static nanocavities,
this limits the ability to tune coupling strength or to couple different
emitters to the same cavity. Here, we present tip-enhanced strong coupling
(TESC) spectroscopy, imaging, and control. Based on a nano-cavity formed
between a scanning plasmonic antenna-tip and the substrate, by reversibly and
dynamically addressing single quantum dots (QDs) we observe mode splitting
> 160 meV and anticrossing over a detuning range of ~100 meV, and with sub-nm precision control over the mode volume in the ~103 nm3 regime. Our
approach, as a new paradigm of nano-cavity quantum-electrodynamics nearfield
microscopy to induce, probe, and control single-emitter plasmon hybrid
quantum states, opens new pathways from opto-electronics to quantum information
science.K.-D. Park, M. A. May, J. Wang, and M. B. Raschke acknowledge funding from the National
Science Foundation (NSF Grant CHE 1709822). H. Leng and M. Pelton acknowledge support
from the National Institute of Standards and Technology under Award Number 14D295. J. A.
Kropp and T. Gougousi acknowledge support from the National Science Foundation under grant ECCS-1407677. Author contributions: M.B.R. and M.P. conceived the experiment. K.-D.P.,
M.A.M, and J.W. performed the measurements. K.-D.P. performed the FDTD simulations. H.L.
performed the FEM simulations. H.L., J.A.K., T.G., and M.P. designed and prepared the samples.
K.-D.P., M.A.M., H.L., M.P., and M.B.R. analysed the data, and all authors discussed the
results. K.-D.P., M.A.M., and M.B.R. wrote the manuscript with contributions from all authors.
M.B.R. supervised the project.https://www.science.org/doi/10.1126/sciadv.aav593
Layout Optimisation of Wave Energy Converter Arrays
No full textThis paper proposes an optimisation strategy for the layout design of wave energy converter (WEC) arrays. Optimal layouts are sought so as to maximise the absorbed power given a minimum q-factor, the minimum distance between WECs, and an area of deployment. To guarantee an efficient optimisation, a four-parameter layout description is proposed. Three different optimisation algorithms are further compared in terms of performance and computational cost. These are the covariance matrix adaptation evolution strategy (CMA), a genetic algorithm (GA) and the glowworm swarm optimisation (GSO) algorithm. The results show slightly higher performances for the latter two algorithms; however, the first turns out to be significantly less computationally demanding
A new species of Croton section Lamprocroton (Euphorbiaceae) from Southern Brazil
No full textCroton longicarpus (Euphorbiaceae), a new species from southern Brazil, is here described and illustrated. The new species occurs in
open vegetation and at the edges of Araucaria forest. The analysis of herbarium collections and observations from populations in the field indicate
that the species has characters in commonwith members of Croton section Lamprocroton. The new species differs from other species in this section by
its unusually elongated ovary and fruit, the narrowly spatulate sepals of the pistillate flowers, and long inflorescences.Financial
support for the first author was provided by ‘Coordenaç~ao de Aperfeiçoamento
de Pessoal de N´ıvel Superior’ (Capes)Peer Reviewe
Reducing variability in the cost of energy of ocean energy arrays
No full textThe research leading to this publication is part of the DTOceanPlus project which has received funding from the EuropeanUnion's Horizon 2020 research and innovation programme under grant agreement No 785921. Funding was also received from the European Community's Seventh Framework Programme for the DTOcean Project (grant agreement No. 608597). The contribution of Sandia National Laboratories was funded by the U.S. Department of Energy's Water Power Technologies Office. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525. This paper describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S. Department of Energy or the United States Government. The image of the RM3 device, in Fig. 7, was reproduced with the permission of Sandia National LaboratoriesVariability in the predicted cost of energy of an ocean energy converter array is more substantial than for other forms of energy generation, due to the combined stochastic action of weather conditions and failures. If the variability is great enough, then this may influence future financial decisions. This paper provides the unique contribution of quantifying variability in the predicted cost of energy and introduces a framework for investigating reduction of variability through investment in components. Following review of existing methodologies for parametric analysis of ocean energy array design, the development of the DTOcean software tool is presented. DTOcean can quantify variability by simulating the design, deployment and operation of arrays with higher complexity than previous models, designing sub-systems at component level. A case study of a theoretical floating wave energy converter array is used to demonstrate that the variability in levelised cost of energy (LCOE) can be greatest for the smallest arrays and that investment in improved component reliability can reduce both the variability and most likely value of LCOE. A hypothetical study of improved electrical cables and connectors shows reductions in LCOE up to 2.51% and reductions in the variability of LCOE of over 50%; these minima occur for different combinations of components.Peer reviewe
