Robust concurrent remote entanglement between two superconducting qubits

Entangling two remote quantum systems which never interact directly is an essential primitive in quantum information science and forms the basis for the modular architecture of quantum computing. When protocols to generate these remote entangled pairs rely on using traveling single photon states as carriers of quantum information, they can be made robust to photon losses, unlike schemes that rely on continuous variable states. However, efficiently detecting single photons is challenging in the domain of superconducting quantum circuits because of the low energy of microwave quanta. Here, we report the realization of a robust form of concurrent remote entanglement based on a novel microwave photon detector implemented in the superconducting circuit quantum electrodynamics (cQED) platform of quantum information. Remote entangled pairs with a fidelity of $0.57\pm0.01$ are generated at $200$ Hz. Our experiment opens the way for the implementation of the modular architecture of quantum computation with superconducting qubits.Comment: Main paper: 7 pages, 4 figures; Appendices: 14 pages, 9 figure

The Transcriptional Landscape of Marek’s Disease Virus in Primary Chicken B Cells Reveals Novel Splice Variants and Genes

Marek’s disease virus (MDV) is an oncogenic alphaherpesvirus that infects chickens and poses a serious threat to poultry health. In infected animals, MDV efficiently replicates in B cells in various lymphoid organs. Despite many years of research, the viral transcriptome in primary target cells of MDV remained unknown. In this study, we uncovered the transcriptional landscape of the very virulent RB1B strain and the attenuated CVI988/Rispens vaccine strain in primary chicken B cells using high-throughput RNA-sequencing. Our data confirmed the expression of known genes, but also identified a novel spliced MDV gene in the unique short region of the genome. Furthermore, de novo transcriptome assembly revealed extensive splicing of viral genes resulting in coding and non-coding RNA transcripts. A novel splicing isoform of MDV UL15 could also be confirmed by mass spectrometry and RT-PCR. In addition, we could demonstrate that the associated transcriptional motifs are highly conserved and closely resembled those of the host transcriptional machinery. Taken together, our data allow a comprehensive re-annotation of the MDV genome with novel genes and splice variants that could be targeted in further research on MDV replication and tumorigenesis

Deterministic nano-assembly of a coupled quantum emitter - photonic crystal cavity system

The interaction of a single quantum emitter with its environment is a central theme in quantum optics. When placed in highly confined optical fields, such as those created in optical cavities or plasmonic structures, the optical properties of the emitter can change drastically. In particular, photonic crystal (PC) cavities show high quality factors combined with an extremely small mode volume. Efficiently coupling a single quantum emitter to a PC cavity is challenging because of the required positioning accuracy. Here, we demonstrate deterministic coupling of single Nitrogen-Vacancy (NV) centers to high-quality gallium phosphide PC cavities, by deterministically positioning their 50 nm-sized host nanocrystals into the cavity mode maximum with few-nanometer accuracy. The coupling results in a 25-fold enhancement of NV center emission at the cavity wavelength. With this technique, the NV center photoluminescence spectrum can be reshaped allowing for efficient generation of coherent photons, providing new opportunities for quantum science.Comment: 13 pages, 4 figure

Dataplane Specialization for High-performance OpenFlow Software Switching

OpenFlow is an amazingly expressive dataplane program- ming language, but this expressiveness comes at a severe performance price as switches must do excessive packet clas- sification in the fast path. The prevalent OpenFlow software switch architecture is therefore built on flow caching, but this imposes intricate limitations on the workloads that can be supported efficiently and may even open the door to mali- cious cache overflow attacks. In this paper we argue that in- stead of enforcing the same universal flow cache semantics to all OpenFlow applications and optimize for the common case, a switch should rather automatically specialize its dat- aplane piecemeal with respect to the configured workload. We introduce ES WITCH , a novel switch architecture that uses on-the-fly template-based code generation to compile any OpenFlow pipeline into efficient machine code, which can then be readily used as fast path. We present a proof- of-concept prototype and we demonstrate on illustrative use cases that ES WITCH yields a simpler architecture, superior packet processing speed, improved latency and CPU scala- bility, and predictable performance. Our prototype can eas- ily scale beyond 100 Gbps on a single Intel blade even with complex OpenFlow pipelines

Why might one expect environmental Kuznets curves? Examining the desirability and feasibility of substitution

This paper provides simple, transparent intuition for the perhaps surprising and certainly widely debated empirical findings of "environmental Kuznets curves", i.e. U-shaped relationships between per-capita income and indicators of environmental quality. We consider one possible component of such relationships: the linkage between income and household choices that impact upon the environment. Our explicit model emphasizes two features. First, degradation of the environmental endowment is a by-product of household activities. We present a household production model in which consumption of marketed commodities generates both a "good", desired non-environmental services, and a "bad", degradation of the environment. Second, while households can not directly purchase environmental quality, they can reorganize their activities so less degradation results. If environmental quality is a normal good, one expects substitution towards less degrading commodities, so that increases in income will increase environmental quality. We show that natural constraints on the desirability and feasibility of such substitution can produce non-monotonic relationships between household income and environmental quality, and in particular can produce household-level environmental Kuznets curves

Endowments, preferences, abatement and voting: Microfoundations of environmental Kuznets curves

Will economic growth inevitably degrade the environment, throughout development? This paper presents a simple household-choice framework that emphasizes the tradeoff between pollution-causing consumption and pollution-reducing abatement expenditures. The framework yields a simple explanation for Environmental Kuznets Curves (EKCs, i.e. non-monotonic, upward-turning paths of environment while development continues) and facilitates analysis of household voting decisions that lead to public regulation of environmental externalities. Our sufficient conditions, more general than the literature, make clear that an asymmetric endowment (i.e. positive environmental quality but zero consumption at zero income) is sufficient for an EKC given standard preferences and a wide range of abatement technologies. The key is that the MRS leads the household to prefer not to abate (or to vote for whatever 'abatement' implies) at low income levels. Without the endowment, abatement technologies alone are insufficient for an EKC path. For a multi-agent setting with externalities, an analogous result is derived in which the chosen tax rate rises with income and environmental quality at first falls and later rises