Generalized multi-photon quantum interference

Non-classical interference of photons lies at the heart of optical quantum information processing. This effect is exploited in universal quantum gates as well as in purpose-built quantum computers that solve the BosonSampling problem. Although non-classical interference is often associated with perfectly indistinguishable photons this only represents the degenerate case, hard to achieve under realistic experimental conditions. Here we exploit tunable distinguishability to reveal the full spectrum of multi-photon non-classical interference. This we investigate in theory and experiment by controlling the delay times of three photons injected into an integrated interferometric network. We derive the entire coincidence landscape and identify transition matrix immanants as ideally suited functions to describe the generalized case of input photons with arbitrary distinguishability. We introduce a compact description by utilizing a natural basis which decouples the input state from the interferometric network, thereby providing a useful tool for even larger photon numbers

Southern Brazilian indigenous populations and the forest: towards an environmental history

Human societies and economies are inextricably linked to oceans and seas. Eight of the world’s ten largest cities lie adjacent to the ocean (UN Atlas of the Oceans, 2010) and about half of the world’s population lives within 200 km of a coast – a quarter within 100 km (IPCC, 2007). Oceans and seas provide a range of ecosystem services (including regulating, provisioning and cultural services) that enhance human well‐being in numerous ways (Millennium Ecosystem Assessment, 2003, 2005; Hicks, 2011). To the extent that climate change affects ecosystems, it will affect fisheries (as discussed in the preceding chapters of this book) and, by extension, human well‐being. In this chapter, we focus on provisioning and cultural services associated with fisheries. Although important, the ocean’s regulating and supporting services, including the fixation of atmospheric carbon, are not further discussed here (for further details, see UNEP‐WCMC, 2011). We describe the numerous contributions of marine‐based ecosystems to human well‐being and the ways in which climate change and other confounding factors are likely to disrupt relationships between fishers, fisheries and fishing communities. Our three case‐studies: small‐scale, artisanal and subsistence‐based fisheries of the western Indian Ocean (WIO), fishing of cultural keystone species in the Torres Strait, and commercial fishing in Australia, serve to highlight the various changes to fisheries likely to be brought about by climate change in three markedly different contexts

Multi-imaging x-ray streak camera for ultrahigh-speed two dimensional x-ray imaging of imploded core plasmas(invited)

Copyright 2004 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Review of Scientific Instruments, 75(10), 3921-3925, 2004 and may be found at http://dx.doi.org/10.1063/1.178924

High-power, kilojoule laser interactions with near-critical density plasma

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98754/1/PhysPlasmas_18_056706.pd

A social-ecological approach to conservation planning: embedding social considerations

Many conservation plans remain unimplemented, in part because of insufficient consideration of the social processes that influence conservation decisions. Complementing social considerations with an integrated understanding of the ecology of a region can result in a more complete conservation approach. We suggest that linking conservation planning to a social-ecological systems (SES) framework can lead to a more thorough understanding of human-environment interactions and more effective integration of social considerations. By characterizing SES as a set of subsystems, and their interactions with each other and with external factors, the SES framework can improve our understanding of the linkages between social and ecological influences on the environment. Using this framework can help to identify socially and ecologically focused conservation actions that will benefit ecosystems and human communities, and assist in the development of more consistent evidence for evaluating conservation actions by comparing conservation case studies

Slowing of Magnetic Reconnection Concurrent with Weakening Plasma Inflows and Increasing Collisionality in Strongly Driven Laser-Plasma Experiments

An evolution of magnetic reconnection behavior, from fast jets to the slowing of reconnection and the establishment of a stable current sheet, has been observed in strongly driven, β ≲ 20 laser-produced plasma experiments. This process has been inferred to occur alongside a slowing of plasma inflows carrying the oppositely directed magnetic fields as well as the evolution of plasma conditions from collisionless to collisional. High-resolution proton radiography has revealed unprecedented detail of the forced interaction of magnetic fields and super-Alfvénic electron jets (V[subscript jet] ~ 20V[subscript A]) ejected from the reconnection region, indicating that two-fluid or collisionless magnetic reconnection occurs early in time. The absence of jets and the persistence of strong, stable magnetic fields at late times indicates that the reconnection process slows down, while plasma flows stagnate and plasma conditions evolve to a cooler, denser, more collisional state. These results demonstrate that powerful initial plasma flows are not sufficient to force a complete reconnection of magnetic fields, even in the strongly driven regime.United States. Dept. of Energy (Grant DE-NA0001857)University of Rochester. Laboratory for Laser Energetics (Grant 415935-G)National Laser User’s Facility (Grant DE-NA0002035)University of Rochester. Fusion Science Center (Grant 5-24431

Assessment of ion kinetic effects in shock-driven inertial confinement fusion implosions using fusion burn imaging

The significance and nature of ion kinetic effects in D3He-filled, shock-driven inertial confinement fusion implosions are assessed through measurements of fusion burn profiles. Over this series of experiments, the ratio of ion-ion mean free path to minimum shell radius (the Knudsen number, NK) was varied from 0.3 to 9 in order to probe hydrodynamic-like to strongly kinetic plasma conditions; as the Knudsen number increased, hydrodynamic models increasingly failed to match measured yields, while an empirically-tuned, first-step model of ion kinetic effects better captured the observed yield trends [Rosenberg et al., Phys. Rev. Lett. 112, 185001 (2014)]. Here, spatially resolved measurements of the fusion burn are used to examine kinetic ion transport effects in greater detail, adding an additional dimension of understanding that goes beyond zero-dimensional integrated quantities to one-dimensional profiles. In agreement with the previous findings, a comparison of measured and simulated burn profiles shows that models including ion transport effects are able to better match the experimental results. In implosions characterized by large Knudsen numbers (NK3), the fusion burn profiles predicted by hydrodynamics simulations that exclude ion mean free path effects are peaked far from the origin, in stark disagreement with the experimentally observed profiles, which are centrally peaked. In contrast, a hydrodynamics simulation that includes a model of ion diffusion is able to qualitatively match the measured profile shapes. Therefore, ion diffusion or diffusion-like processes are identified as a plausible explanation of the observed trends, though further refinement of the models is needed for a more complete and quantitative understanding of ion kinetic effects

Implosion hydrodynamics of fast ignition targets

Copyright 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physics of Plasmas, 12(5), 056312, 2005 and may be found at http://dx.doi.org/10.1063/1.189695