1,614 research outputs found
Efficient Simulation of Structural Faults for the Reliability Evaluation at System-Level
In recent technology nodes, reliability is considered a part of the standard design ¿ow at all levels of embedded system design. While techniques that use only low-level models at gate- and register transfer-level offer high accuracy, they are too inefficient to consider the overall application of the embedded system. Multi-level models with high abstraction are essential to efficiently evaluate the impact of physical defects on the system. This paper provides a methodology that leverages state-of-the-art techniques for efficient fault simulation of structural faults together with transaction-level modeling. This way it is possible to accurately evaluate the impact of the faults on the entire hardware/software system. A case study of a system consisting of hardware and software for image compression and data encryption is presented and the method is compared to a standard gate/RT mixed-level approac
Absence of skew scattering in two-dimensional systems: Testing the origins of the anomalous Hall effect
We study the anomalous Hall conductivity in spin-polarized, asymmetrically
confined two-dimensional electron and hole systems, focusing on skew-scattering
contributions to the transport. We find that the skew scattering, principally
responsible for the extrinsic contribution to the anomalous Hall effect,
vanishes for the two-dimensional electron system if both chiral Rashba subbands
are partially occupied, and vanishes always for the two-dimensional hole gas
studied here, regardless of the band filling. Our prediction can be tested with
the proposed coplanar two-dimensional electron/hole gas device and can be used
as a benchmark to understand the crossover from the intrisic to the extrinsic
anomalous Hall effect.Comment: 4 pages, 2 figures include
Digital, memory and mixed-signal test engineering education: five centres of competence in Europe
The launching of the EuNICE-Test project was announced two years ago at the first DELTA Conference. This project is now completed and the present paper describes the project actions and outcomes. The original idea was to build a long-lasting European Network for test engineering education using both test resource mutualisation and remote experiments. This objective is fully fulfilled and we have now, in Europe, five centres of competence able to deliver high-level and high-specialized training courses in the field of test engineering using a high-performing industrial ATE. All the centres propose training courses on digital testing, three of them propose mixed-signal trainings and three of them propose memory trainings. Taking into account the demand in test engineering, the network is planned to continue in a stand alone mode after project end. Nevertheless a new European proposal with several new partners and new test lessons is under construction
Simulation of a quantum phase transition of polaritons with trapped ions
We present a novel system for the simulation of quantum phase transitions of
collective internal qubit and phononic states with a linear crystal of trapped
ions. The laser-ion interaction creates an energy gap in the excitation
spectrum, which induces an effective phonon-phonon repulsion and a
Jaynes-Cummings-Hubbard interaction. This system shows features equivalent to
phase transitions of polaritons in coupled cavity arrays. Trapped ions allow
for easy tunabilty of the hopping frequency by adjusting the axial trapping
frequency, and the phonon-phonon repulsion via the laser detuning and
intensity. We propose an experimental protocol to access all observables of the
system, which allows one to obtain signatures of the quantum phase transitions
even with a small number of ions.Comment: 4 pages, 3 figure
Test engineering education in Europe: the EuNICE-Test project
The paper deals with a European experience of education in industrial test of ICs and SoCs using remote testing facilities. The project addresses the problem of the shortage in microelectronics engineers aware with the new challenge of testing mixed-signal SoCs far multimedia/telecom market. It aims at providing test training facilities at a European scale in both initial and continuing education contexts. This is done by allowing the academic and industrial partners of the consortium to train engineers using the common test resources center (CRTC) hosted by LIRMM (Laboratoire d'Informatique, de Robotique et de Microelectronique de Montpellier, France). CRTC test tools include up-to-date/high-tech testers that are fully representative of real industrial testers as used on production testfloors. At the end of the project, it is aimed at reaching a cruising speed of about 16 trainees per year per center. Each trainee will have attend at least one one-week training using the remote test facilities of CRTC
Quantum Gates and Memory using Microwave Dressed States
Trapped atomic ions have been successfully used for demonstrating basic
elements of universal quantum information processing (QIP). Nevertheless,
scaling up of these methods and techniques to achieve large scale universal
QIP, or more specialized quantum simulations remains challenging. The use of
easily controllable and stable microwave sources instead of complex laser
systems on the other hand promises to remove obstacles to scalability.
Important remaining drawbacks in this approach are the use of magnetic field
sensitive states, which shorten coherence times considerably, and the
requirement to create large stable magnetic field gradients. Here, we present
theoretically a novel approach based on dressing magnetic field sensitive
states with microwave fields which addresses both issues and permits fast
quantum logic. We experimentally demonstrate basic building blocks of this
scheme to show that these dressed states are long-lived and coherence times are
increased by more than two orders of magnitude compared to bare magnetic field
sensitive states. This changes decisively the prospect of microwave-driven ion
trap QIP and offers a new route to extend coherence times for all systems that
suffer from magnetic noise such as neutral atoms, NV-centres, quantum dots, or
circuit-QED systems.Comment: 9 pages, 4 figure
The application of reliability methods in the design of stiffened FRP composite panels for marine vessels
The use of composite laminate materials has increased rapidly in recent years due to their excellent strength to weight ratio and resistance to corrosion. In the construction of marine vessels, stiffened plates are the most commonly used structural elements, forming the deck, bottom hull, side shells and bulkheads. This paper presents the use of a stochastic approach to the design of stiffened marine composite panels as part of a current research programme into developing stochastic methods for composite ship structures, accounting for variations in material properties, geometric indices and processing techniques, from the component level to the full system level. An analytical model for the solution of a stiffened isotropic plate using a grillage analogy is extended by the use of equivalent elastic properties for composite modelling. This methodology is applied in a reliability analysis of an isotropic (steel) stiffened plate before the final application for a reliability analysis for a FRP composite stiffened plate
High-fidelity state detection and tomography of a single ion Zeeman qubit
We demonstrate high-fidelity Zeeman qubit state detection in a single trapped
88 Sr+ ion. Qubit readout is performed by shelving one of the qubit states to a
metastable level using a narrow linewidth diode laser at 674 nm followed by
state-selective fluorescence detection. The average fidelity reached for the
readout of the qubit state is 0.9989(1). We then measure the fidelity of state
tomography, averaged over all possible single-qubit states, which is 0.9979(2).
We also fully characterize the detection process using quantum process
tomography. This readout fidelity is compatible with recent estimates of the
detection error-threshold required for fault-tolerant computation, whereas
high-fidelity state tomography opens the way for high-precision quantum process
tomography
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