488,469 research outputs found
Universal Three Dimensional Optical Logic
Modern integrated circuits are essentially two-dimensional (2D). Partial
three-dimensional (3D) integration and 3D-transistor-level integrated circuits
have long been anticipated as routes to improve the performance, cost and size
of electronic computing systems. Even as electronics approach fundamental
limits however, stubborn challenges in 3D circuits, and innovations in planar
technology have delayed the dimensional transition. Optical computing offers
potential for new computing approaches, substantially greater performance and
would complement technologies in optical interconnects and data storage.
Nevertheless, despite some progress, few proposed optical transistors possess
essential features required for integration into real computing systems. Here
we demonstrate a logic gate based on universal features of nonlinear wave
propagation: spatiotemporal instability and collapse. It meets the scaling
criteria and enables a 3D, reconfigurable, globally-hyperconnected architecture
that may achieve an exponential speed up over conventional platforms. It
provides an attractive building block for future optical computers, where its
universality should facilitate flexible implementations.Comment: manuscript (5 pages, 3 figures) with supplementary information (6
pages, 5 figures
Three-dimensional surface codes: Transversal gates and fault-tolerant architectures
One of the leading quantum computing architectures is based on the
two-dimensional (2D) surface code. This code has many advantageous properties
such as a high error threshold and a planar layout of physical qubits where
each physical qubit need only interact with its nearest neighbours. However,
the transversal logical gates available in 2D surface codes are limited. This
means that an additional (resource intensive) procedure known as magic state
distillation is required to do universal quantum computing with 2D surface
codes. Here, we examine three-dimensional (3D) surface codes in the context of
quantum computation. We introduce a picture for visualizing 3D surface codes
which is useful for analysing stacks of three 3D surface codes. We use this
picture to prove that the and gates are transversal in 3D surface
codes. We also generalize the techniques of 2D surface code lattice surgery to
3D surface codes. We combine these results and propose two quantum computing
architectures based on 3D surface codes. Magic state distillation is not
required in either of our architectures. Finally, we show that a stack of three
3D surface codes can be transformed into a single 3D color code (another type
of quantum error-correcting code) using code concatenation.Comment: 23 pages, 24 figures, v2: published versio
Computing shortest paths in 2D and 3D memristive networks
Global optimisation problems in networks often require shortest path length
computations to determine the most efficient route. The simplest and most
common problem with a shortest path solution is perhaps that of a traditional
labyrinth or maze with a single entrance and exit. Many techniques and
algorithms have been derived to solve mazes, which often tend to be
computationally demanding, especially as the size of maze and number of paths
increase. In addition, they are not suitable for performing multiple shortest
path computations in mazes with multiple entrance and exit points. Mazes have
been proposed to be solved using memristive networks and in this paper we
extend the idea to show how networks of memristive elements can be utilised to
solve multiple shortest paths in a single network. We also show simulations
using memristive circuit elements that demonstrate shortest path computations
in both 2D and 3D networks, which could have potential applications in various
fields
System-Level Design of Energy-Proportional Many-Core Servers for Exascale Computing
Continuous advances in manufacturing technologies are enabling the development of more powerful and compact high-performance computing (HPC) servers made of many-core processing architectures.
However, this soaring demand for computing power in the last years has grown faster than emiconductor technology evolution can sustain, and has produced as collateral undesirable effect a surge in power consumption and heat density in these new HPC servers, which result on significant performance degradation. In this keynote, I advocate to completely revise the current HPC
server architectures. In particular, inspired by the mammalian brain, I propose to design a disruptive three-dimensional (3D) computing
server architecture that overcomes the prevailing worst-case power and cooling provisioning paradigm for servers. This new 3D server design champions a new system-level thermal modeling, which can be
used by novel proactive energy controllers for detailed heat and energy management in many-core HPC servers, thanks to micro-scale liquid cooling. Then, I will show the impact of new near-threshold
computing architectures on server design, and how we can integrate new on-chip microfluidic fuel cell networks to enable energy-scalability in future generations of many-core HPC servers
targeting Exascale computing.Universidad de Málaga, Campus de Excelencia Internacional AndalucĂa Tech
Accurate and efficient numerical methods for computing ground states and dynamics of dipolar Bose-Einstein condensates via the nonuniform FFT
In this paper, we propose efficient and accurate numerical methods for
computing the ground state and dynamics of the dipolar Bose-Einstein
condensates utilising a newly developed dipole-dipole interaction (DDI) solver
that is implemented with the non-uniform fast Fourier transform (NUFFT)
algorithm. We begin with the three-dimensional (3D) Gross-Pitaevskii equation
(GPE) with a DDI term and present the corresponding two-dimensional (2D) model
under a strongly anisotropic confining potential. Different from existing
methods, the NUFFT based DDI solver removes the singularity by adopting the
spherical/polar coordinates in Fourier space in 3D/2D, respectively, thus it
can achieve spectral accuracy in space and simultaneously maintain high
efficiency by making full use of FFT and NUFFT whenever it is necessary and/or
needed. Then, we incorporate this solver into existing successful methods for
computing the ground state and dynamics of GPE with a DDI for dipolar BEC.
Extensive numerical comparisons with existing methods are carried out for
computing the DDI, ground states and dynamics of the dipolar BEC. Numerical
results show that our new methods outperform existing methods in terms of both
accuracy and efficiency.Comment: 26 pages, 5 figure
Detector and Event Visualization with SketchUp at the CMS Experiment
We have created 3D models of the CMS detector and particle collision events
in SketchUp, a 3D modelling program. SketchUp provides a Ruby API which we use
to interface with the CMS Detector Description to create 3D models of the CMS
detector. With the Ruby API, we also have created an interface to the
JSON-based event format used for the iSpy event display to create 3D models of
CMS events. These models have many applications related to 3D representation of
the CMS detector and events. Figures produced based on these models were used
in conference presentations, journal publications, technical design reports for
the detector upgrades, art projects, outreach programs, and other
presentations.Comment: 5 pages, 6 figures, Proceedings for CHEP 2013, 20th International
Conference on Computing in High Energy and Nuclear Physic
- …