Progress in Spin Glasses and Random Fields – Research with a Special Purpose Computer

1985 ◽  
Vol 63 ◽  
Author(s):  
A. T. Ogielski
Keyword(s):  
Numerical Simulations ◽  
Spin Glass ◽  
Magnetic Materials ◽  
Random Fields ◽  
Spin Glasses ◽  
Three Dimensional ◽  
Purpose Computer ◽  
Special Purpose Computer

ABSTRACTExtensive numerical simulations of random magnetic materials have been recently performed at AT&T Bell Laboratories with a fast specially designed computer. I will discuss certain issues concerning the use of specialized computers in research, and I will review some major results obtained in simulations of a three-dimensional spin glass and an antiferromagnet with random fields.

CHIRAL ORDER IN SPIN GLASSES

1996 ◽  
Vol 07 (03) ◽  
pp. 345-353 ◽  
Author(s):  
HIKARU KAWAMURA
Keyword(s):  
Numerical Simulations ◽  
Spin Glass ◽  
Spin Glasses ◽  
Spin Rotation ◽  
Reflection Symmetry ◽  
The Novel ◽  
Glass Transitions ◽  
Rotation Symmetry ◽  
Numerical Evidence ◽  
Chiral Glass

The results of the recent numerical simulations on vector spin glasses are presented. Numerical evidence of the novel chiral-glass state, accompanied with broken spin-reflection symmetry with preserving spin-rotation symmetry, is presented. Implication to experiments on spin-glass transitions is discussed.

GROUND STATES IN THREE-DIMENSIONAL ±J EDWARDS–ANDERSON SPIN GLASSES WITH FREE BOUNDARIES

2000 ◽  
Vol 11 (03) ◽  
pp. 589-592
Author(s):  
FRAUKE LIERS ◽  
MICHAEL JÜNGER
Keyword(s):  
Spin Glass ◽  
Spin Glasses ◽  
State Energy ◽  
Infinite System ◽  
Three Dimensional ◽  
Finite Size ◽  
Ground States ◽  
Free Boundaries ◽  
Finite Size Corrections

By an exact calculation of the ground states for the ±J Edwards–Anderson spin glass, one can extrapolate the ground state energy to infinite system sizes. We calculate the exact ground states for the three-dimensional spin glass with free boundaries for system sizes up to 10 and fit different finite-size functions. We cannot decide, only from the quality of the fit, which fitting function to choose. Relying on the literature values for the extrapolated energy, we find the finite-size corrections to vary as 1/L.

scholarly journals MDGRAPE-4: a special-purpose computer system for molecular dynamics simulations

2014 ◽  
Vol 372 (2021) ◽  
pp. 20130387 ◽  
Author(s):  
Itta Ohmura ◽  
Gentaro Morimoto ◽  
Yousuke Ohno ◽  
Aki Hasegawa ◽  
Makoto Taiji
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Computer System ◽  
Three Dimensional ◽  
Md Simulations ◽  
Particle Simulation ◽  
Peak Performance ◽  
Dynamics Simulations ◽  
Purpose Computer ◽  
Special Purpose Computer

We are developing the MDGRAPE-4, a special-purpose computer system for molecular dynamics (MD) simulations. MDGRAPE-4 is designed to achieve strong scalability for protein MD simulations through the integration of general-purpose cores, dedicated pipelines, memory banks and network interfaces (NIFs) to create a system on chip (SoC). Each SoC has 64 dedicated pipelines that are used for non-bonded force calculations and run at 0.8 GHz. Additionally, it has 65 Tensilica Xtensa LX cores with single-precision floating-point units that are used for other calculations and run at 0.6 GHz. At peak performance levels, each SoC can evaluate 51.2 G interactions per second. It also has 1.8 MB of embedded shared memory banks and six network units with a peak bandwidth of 7.2 GB s −1 for the three-dimensional torus network. The system consists of 512 (8×8×8) SoCs in total, which are mounted on 64 node modules with eight SoCs. The optical transmitters/receivers are used for internode communication. The expected maximum power consumption is 50 kW. While MDGRAPE-4 software has still been improved, we plan to run MD simulations on MDGRAPE-4 in 2014. The MDGRAPE-4 system will enable long-time molecular dynamics simulations of small systems. It is also useful for multiscale molecular simulations where the particle simulation parts often become bottlenecks.

scholarly journals SUE: A special purpose computer for spin glass models

2001 ◽  
Vol 133 (2-3) ◽  
pp. 165-176 ◽  
Author(s):  
A Cruz ◽  
J Pech ◽  
A Tarancón ◽  
P Téllez ◽  
C.L Ullod ◽  
...  
Keyword(s):  
Spin Glass ◽  
Purpose Computer ◽  
Special Purpose Computer

scholarly journals PRECISE DETERMINATION OF THE CONDUCTIVITY EXPONENT OF 3D PERCOLATION USING "PERCOLA"

1996 ◽  
Vol 06 (06) ◽  
pp. 813-817 ◽  
Author(s):  
JEAN-MARIE NORMAND ◽  
HANS J. HERRMANN
Keyword(s):  
Three Dimensional ◽  
Precise Determination ◽  
Bond Percolation ◽  
Cpu Time ◽  
A Value ◽  
Correction To Scaling ◽  
Purpose Computer ◽  
Special Purpose Computer

Using 20 months of CPU time on our special purpose computer "Percola" we determined the exponent for the normal conductivity at the threshold of three-dimensional site and bond percolation. The extrapolation analysis taking into account the first correction to scaling gives a value of t/ν = 2.26±0.04 and a correction exponent ω around 1.4.

RANDOM JOSEPHSON NETWORKS AND SPIN GLASSES

1987 ◽  
Vol 01 (01n02) ◽  
pp. 27-37 ◽  
Author(s):  
M.V. FEIGEL’MAN ◽  
L.B. IOFFE ◽  
A.I. LARKIN ◽  
V.M. VINOKUR
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Numerical Simulations ◽  
Spin Glass ◽  
Spin Glasses ◽  
Equations Of State ◽  
Analytical Theory ◽  
Diamagnetic Response ◽  
The Magnetic Field

The phase transition into a spin glass-like state is predicted for the system of superconductive wires connected by Josephson links and placed into the magnetic field. History-dependent equations of state for T<Tc are derived and diamagnetic response to the variation of the magnetic field is predicted. The experiments that can solve the discrepancy between the analytical theory and the numerical simulations on the existence of the phase transition in the vector spin glasses are discussed.

scholarly journals Special-purpose computer for digital holographic high-speed three-dimensional imaging

2020 ◽  
Vol 59 (05) ◽  
pp. 1 ◽  
Author(s):  
Yota Yamamoto ◽  
Shintaro Namba ◽  
Takashi Kakue ◽  
Tomoyoshi Shimobaba ◽  
Tomoyoshi Ito ◽  
...  
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Three Dimensional Imaging ◽  
Purpose Computer ◽  
Special Purpose Computer

scholarly journals THE CLUSTER PROCESSOR: NEW RESULTS

1999 ◽  
Vol 10 (06) ◽  
pp. 1137-1148 ◽  
Author(s):  
HENK W. J. BLÖTE ◽  
LEV. N. SHCHUR ◽  
ANDREI L. TALAPOV
Keyword(s):  
Ising Model ◽  
Nearest Neighbor ◽  
Three Dimensional ◽  
Universality Class ◽  
Scaling Exponent ◽  
Monte Carlo Data ◽  
Correction To Scaling ◽  
Purpose Computer ◽  
Special Purpose Computer

We present a progress report on the Cluster Processor, a special-purpose computer system for the Wolff simulation of the three-dimensional Ising model, including an analysis of simulation results obtained thus far. These results allow, within narrow error margins, a determination of the parameters describing the phase transition of the simple-cubic Ising model and its universality class. For an improved determination of the correction-to-scaling exponent, we include Monte Carlo data for systems with nearest-neighbor and third-neighbor interactions in the analysis.

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