Harvesting Excitons Through Plasmonic Strong Coupling

Exciton harvesting is demonstrated in an ensemble of quantum emitters coupled to localized surface plasmons. When the interaction between emitters and the dipole mode of a metallic nanosphere reaches the strong coupling regime, the exciton conductance is greatly increased. The spatial map of the conductance matches the plasmon field intensity profile, which indicates that transport properties can be tuned by adequately tailoring the field of the plasmonic resonance. Under strong coupling, we find that pure dephasing can have detrimental or beneficial effects on the conductance, depending on the effective number of participating emitters. Finally, we show that the exciton transport in the strong coupling regime occurs on an ultrafast timescale given by the inverse Rabi splitting ($\sim10~$fs), orders of magnitude faster than transport through direct hopping between the emitters.Comment: 5 pages, 3 figure

Noise Control And Speech Intelligibility Improvement Of A Toll Plaza

Vehicular toll roads are one component of many municipal transportation systems. Open communication windows, often used in tollbooths, facilitate essential communication and monetary transactions. However, the vehicle noise generated outside the booth is easily transmitted into the booth via the open window. Personnel working at toll collection plazas are exposed to extended, continuous traffic noise. Sustained noise levels of this nature may cause hearing loss, induce fatigue or stress, and reduce worker productivity. The annoyance and discomfort related to continuous noise exposure may create an unpleasant working condition and may affect the hospitality of the tollbooth operators and their attitude toward customers. Furthermore, the noise level may hinder communication with customers and may compromise safety. Reduction of the noise level and an improvement in speech intelligibility are highly desirable. The acoustics of a typical toll plaza and structural noise control strategies were modeled using a beam tracing technique. Noise control strategies involved the application sound absorbing material to the overhead canopy, the construction of sound absorbing partial barriers, and the treatment of tollbooth walls with sound absorbing material. In terms of noise control, the results suggest that the direct field is more important that the reflected field. The effects of active noise control (ANC) systems to reduce traffic noise and improve speech intelligibility at the toll plaza was investigated. The ANC systems included a range of headsets and a prototype external unit designed to create a local region of attenuation. Significant noise reduction can be achieved with a sealed, closed ear ANC headsets. However, the various systems seemed to have little positive effect upon speech intelligibility under traffic noise conditions. The result imply that the signal to noise ratio under toll plaza conditions is poor and that level overloading effects may further reduce intelligibility. Altered systems were modeled to improve the signal to noise ratio and reduce the noise level. The improved systems utilize a directional microphone and a sealed ANC headset. With a high order directional microphone, good speech intelligibility is achievable even in the presence of toll plaza vehicle noise

Nano-wires with surface disorder: Giant localization lengths and quantum-to-classical crossover

We investigate electronic quantum transport through nano-wires with one-sided surface roughness. A magnetic field perpendicular to the scattering region is shown to lead to exponentially diverging localization lengths in the quantum-to-classical crossover regime. This effect can be quantitatively accounted for by tunneling between the regular and the chaotic components of the underlying mixed classical phase space.Comment: 4 pages, 3 figures; final version (including added references

Nanoplasmonic Lattices for Ultracold atoms

We propose to use sub-wavelength confinement of light associated with the near field of plasmonic systems to create nanoscale optical lattices for ultracold atoms. Our approach combines the unique coherence properties of isolated atoms with the sub-wavelength manipulation and strong light-matter interaction associated with nano-plasmonic systems. It allows one to considerably increase the energy scales in the realization of Hubbard models and to engineer effective long-range interactions in coherent and dissipative many-body dynamics. Realistic imperfections and potential applications are discussed.Comment: 5 pages, 3 figures, V2: minor changes, V3: minor changes, added supplemental materia

Documenting of Geologic Field Activities in Real-Time in Four Dimensions: Apollo 17 as a Case Study for Terrestrial Analogues and Future Exploration

During the Apollo exploration of the lunar surface, thousands of still images, 16 mm videos, TV footage, samples, and surface experiments were captured and collected. In addition, observations and descriptions of what was observed was radioed to Mission Control as part of standard communications and subsequently transcribed. The archive of this material represents perhaps the best recorded set of geologic field campaigns and will serve as the example of how to conduct field work on other planetary bodies for decades to come. However, that archive of material exists in disparate locations and formats with varying levels of completeness, making it not easily cross-referenceable. While video and audio exist for the missions, it is not time synchronized, and images taken during the missions are not time or location tagged. Sample data, while robust, is not easily available in a context of where the samples were collected, their descriptions by the astronauts are not connected to them, or the video footage of their collection (if available). A more than five year undertaking to reconstruct and reconcile the Apollo 17 mission archive, from launch through splashdown, has generated an integrated record of the entire mission, resulting in searchable, synchronized image, voice, and video data, with geologic context provided at the time each sample was collected. Through www.apollo17.org the documentation of the field investigation conducted by the Apollo 17 crew is presented in chronologic sequence, with additional context provided by high-resolution Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) images and a corresponding digital terrain model (DTM) of the Taurus-Littrow Valley

Nonlocal damage based failure models, extraction of crack opening and transition to fracture

International audienceDamage models are capable to represent initiation and somehow crack propagation in a continuum framework. Thus crack openings are not explicitly described. However for concrete structures durability analysis, crack opening through transfer properties is a key issue. Therefore, in this contribution we present a new approach that is able from a continuum modelling to locate a crack from internal variable field and then to estimate crack opening along its path. Results compared to experimental measures for a three point bending test are in a good agreement with an error lower than 10% for widely opened crack (40μm)

Dispensability of Escherichia coli's latent pathways

Gene-knockout experiments on single-cell organisms have established that expression of a substantial fraction of genes is not needed for optimal growth. This problem acquired a new dimension with the recent discovery that environmental and genetic perturbations of the bacterium Escherichia coli are followed by the temporary activation of a large number of latent metabolic pathways, which suggests the hypothesis that temporarily activated reactions impact growth and hence facilitate adaptation in the presence of perturbations. Here we test this hypothesis computationally and find, surprisingly, that the availability of latent pathways consistently offers no growth advantage, and tends in fact to inhibit growth after genetic perturbations. This is shown to be true even for latent pathways with a known function in alternate conditions, thus extending the significance of this adverse effect beyond apparently nonessential genes. These findings raise the possibility that latent pathway activation is in fact derivative of another, potentially suboptimal, adaptive response