58 research outputs found
A system design approach toward integrated cryogenic quantum control systems
In this paper, we provide a system level perspective on the design of control
electronics for large scale quantum systems. Quantum computing systems with
high-fidelity control and readout, coherent coupling, calibrated gates, and
reconfigurable circuits with low error rates are expected to have superior
quantum volumes. Cryogenic CMOS plays a crucial role in the realization of
scalable quantum computers, by minimizing the feature size, lowering the cost,
power consumption, and implementing low latency error correction. Our approach
toward achieving scalable feed-back based control systems includes the design
of memory based arbitrary waveform generators (AWG's), wide band radio
frequency analog to digital converters, integrated amplifier chain, and state
discriminators that can be synchronized with gate sequences. Digitally assisted
designs, when implemented in an advanced CMOS node such as 7 nm can reap the
benefits of low power due to scaling. A qubit readout chain demands several
amplification stages before the digitizer. We propose the co-integration of our
in-house developed InP HEMT LNAs with CMOS LNA stages to achieve the required
gain at the digitizer input with minimal area. Our approach using high
impedance matching between the HEMT LNA and the cryogenic CMOS receiver can
relax the design constraints of an inverter-based CMOS LNA, paving the way
toward a fully integrated qubit readout chain. The qubit state discriminator
consists of a digital signal processor that computes the qubit state from the
digitizer output and a pre-determined threshold. The proposed system realizes
feedback-based optimal control for error mitigation and reduction of the
required data rate through the serial interface to room temperature
electronics
Mapping and Evaluating Marine Protected Areas and Ecosystem Services: A Transdisciplinary Delphi Forecasting Process Framework
Marine Protected Areas (MPAs) are an important tool for management and conservation and play an increasingly recognised role in societal and human well-being. However, the assessment of MPAs often lacks a simultaneous consideration of ecological and socio-economic outcomes, and this can lead to misconceptions on the effectiveness of MPAs. In this perspective, we present a transdisciplinary approach based on the Delphi method for mapping and evaluating Marine Protected Areas for their ability to protect biodiversity while providing Ecosystem Services (ES) and related human well-being benefits - i.e., the ecosystem outputs from which people benefit. We highlight the need to include the human dimensions of marine protection in such assessments, given that the effectiveness of MPAs over time is conditional on the social, cultural and institutional contexts in which MPAs evolve. Our approach supports Ecosystem-Based Management and highlights the importance of MPAs in achieving restoration, conservation, and sustainable development objectives in relation to EU Directives such as the Marine Strategy Framework Directive (MSFD), the Maritime Spatial Planning Directive (MSPD), and the Common Fisheries Policy (CFP)
Conformal Symmetry and Universal Properties of Quantum Hall States
The low-lying excitations of a quantum Hall state on a disk geometry are edge
excitations. Their dynamics is governed by a conformal field theory on the
cylinder defined by the disk boundary and the time variable. We give a simple
and detailed derivation of this conformal field theory for integer filling,
starting from the microscopic dynamics of -dimensional non-relativistic
electrons in Landau levels. This construction can be generalized to describe
Laughlin's fractional Hall states via chiral bosonization, thereby making
contact with the effective Chern-Simons theory approach. The conformal field
theory dictates the finite-size effects in the energy spectrum. An experimental
or numerical verification of these universal effects would provide a further
confirmation of Laughlin's theory of incompressible quantum fluids.Comment: 39 pages, 7 figures (not included, they are mailed on request),
harvmac CERN-TH 6702/9
An Eight lanes 7Gb/s/pin Source Synchronous Single-Ended RX with Equalization and Far-End Crosstalk Cancellation for Backplane Channels
This paper presents a versatile crosstalk cancellation scheme for single-ended multi-lane backplane links. System-level investigations show that a scheme, which combines analog filters and decision-feedback crosstalk compensation on the receiver (RX) side only, can efficiently remove crosstalk patterns in straight channels as well as boards with reflections due to via stubs. An eight-lane single-ended RX has been manufactured in 32-nm SOI CMOS to validate our findings. A CTLE and eight-tap decision feedback equalizer equalize the channel without transmitter feedforward equalizer. A continuous time crosstalk canceller reduces precursors by nearest neighbors, while the residual postcursors from all aggressors are suppressed by direct feedback 7x8-tap decision-feedback crosstalk canceller (DFXC). Measurements with flip-chip packaged RX show that the RX macro can equalize both a 30-dB insertion loss single-ended channel with 0-dB signal-to-crosstalk at Nyquist and a channel with 28-dB attenuation with the signal-to-crosstalk ratio of 6 dB combined with reflections due to via stubs. The RX operates up to 7 Gb/s/pin with PRBS11 data at bit error rate (BER) <10⁻¹², and occupies 300x350 μm² with an energy efficiency of 5.9 mW/Gb/s from 1-V supply
A 5.9mW/Gb/s 7Gb/s/pin 8-Lane Single-Ended RX with Crosstalk Cancellation Scheme using a XCTLE and 56-tap XDFE in 32nm SOI CMOS
This work reports an 8-lane single-ended RX featuring compact and low power far-end crosstalk (FEXT) cancellation circuits. The RX data-path consists of a cross continuous-time linear equalizer (XCTLE) to remove FEXT by nearest aggressors within the channel bundle. Residual post-cursor FEXT is suppressed by a direct feedback 7x8-tap cross decision feedback equalizer (XDFE). A CTLE and 8-tap DFE equalize single-ended channels with 28dB insertion loss at Nyquist frequency without TX FFE. The circuit, fabricated in 32nm SOI CMOS, was measured to receive 7Gb/s/pin PRBS11 data at BER< 10^-12 with 12.5%UI margin. It occupies 300x350um2 with an energy efficiency of 5.9mW/Gb/s
Parafermion Hall states from coset projections of abelian conformal theories
The Z_k-parafermion Hall state is an incompressible fluid of k-electron
clusters generalizing the Pfaffian state of paired electrons. Extending our
earlier analysis of the Pfaffian, we introduce two ``parent'' abelian Hall
states which reduce to the parafermion state by projecting out some neutral
degrees of freedom. The first abelian state is a generalized (331) state which
describes clustering of k distinguishable electrons and reproduces the
parafermion state upon symmetrization over the electron coordinates. This
description yields simple expressions for the quasi-particle wave functions of
the parafermion state. The second abelian state is realized by a conformal
theory with a (2k-1)-dimensional chiral charge lattice and it reduces to the
Z_k-parafermion state via the coset construction su(k)_1+su(k)_1/su(k)_2. The
detailed study of this construction provides us a complete account of the
excitations of the parafermion Hall state, including the field identifications,
the Z_k symmetry and the partition function.Comment: Latex, 36 pages, 3 tables, 2 figure
Identification of Giardia lamblia DHHC Proteins and the Role of Protein S-palmitoylation in the Encystation Process
Protein S-palmitoylation, a hydrophobic post-translational modification, is performed by protein acyltransferases that have a common DHHC Cys-rich domain (DHHC proteins), and provides a regulatory switch for protein membrane association. In this work, we analyzed the presence of DHHC proteins in the protozoa parasite Giardia lamblia and the function of the reversible S-palmitoylation of proteins during parasite differentiation into cyst. Two specific events were observed: encysting cells displayed a larger amount of palmitoylated proteins, and parasites treated with palmitoylation inhibitors produced a reduced number of mature cysts. With bioinformatics tools, we found nine DHHC proteins, potential protein acyltransferases, in the Giardia proteome. These proteins displayed a conserved structure when compared to different organisms and are distributed in different monophyletic clades. Although all Giardia DHHC proteins were found to be present in trophozoites and encysting cells, these proteins showed a different intracellular localization in trophozoites and seemed to be differently involved in the encystation process when they were overexpressed. dhhc transgenic parasites showed a different pattern of cyst wall protein expression and yielded different amounts of mature cysts when they were induced to encyst. Our findings disclosed some important issues regarding the role of DHHC proteins and palmitoylation during Giardia encystation.Fil: Merino, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Zamponi, Nahuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Vranych, Cecilia Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Touz, Maria Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; ArgentinaFil: Ropolo, Andrea Silvana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra. Universidad Nacional de Córdoba. Instituto de Investigación Médica Mercedes y Martín Ferreyra; Argentin
BONUS BASMATI Thematic Scoping/Vision Document: report outlining the main conflict and potential synergy areas in crossborder MSP. Deliverable 2.2
Addressing conflicts between marine interests and finding workable
solutions that can facilitate synergies between stakeholders is an important
task of spatial planning both onshore and in the sea. A general assumption
among many experts in marine/maritime spatial planning (MSP) is that promoting
synergies and coexistence can enhance spatial efficiency of marine uses and
possibly result in a more sustainable use of marine resources. However, in
order to promote cooperation, one needs to first establish a better
understanding of the crucial components of conflictive and synergetic planning
situations and important definitions related to this.
This scoping report examines conceptualisations and analytical perspectives
on work with conflicts and synergies in MSP in relation to the case studies of
the BONUS BASMATI project. The theme of conflicts and synergies is rather
topical, not least in connection with attempts of the EU and other actors to
promote growth in the blue economic sector and keep related environmental
impacts low. MSP is seen as an important tool or approach to promote and
achieve these goals (European Commission 2008; European Commission 2009;
European Commission 2012).
Chapter 1 provides introductory reflections on conflicts and
synergies in marine spatial planning using both an analytical narrative
complemented with examples from conflict theory. The aim is to provide the
reader with an easily understandable introduction into relevant terms used and
important issues to be considered when working with conflicts and synergies in
MSP. These include interests, stakeholders, institutional frameworks, rules,
systems and practices, space and geography, knowledge and technologies,
conflict-synergies in a broader context. The chapter concludes with an analysis
of conflict analysis and management literature and a discussion on the
potential role of conflict management in MSP.
Chapter 2 provides examples of conflicts and obstacles that have
emerged in a Baltic Sea Region (BSR) context and how, through people, planning
processes, projects and institutions synergies have been developed. The chapter
focuses on 1) Conflicts of interest: Marine use related conflicts / obstacles
and synergies, 2) Institutional cross-border conflicts / obstacles and
synergies, 3) Process related conflicts / obstacles and synergies, 4) Knowledge
and data related conflicts / obstacles and synergies, 5) Other types of obstacles
that are context related.
Chapter 3 zooms in on the three BONUS BASMATI case studies and
highlights emerging and potential conflicts and synergies within the case study
areas. It also suggests potential synergies and solutions for overcoming
challenges that can be addressed in the case studies and during the lifetime of
the project.</p
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