Parallel multi-teraflops studies of the magnetic structure of FeMn alloys

A. Canning, B. Ujfalussy, T. C. Schulthess, X. G. Zhang, W. A. Shelton, D. M.C. Nicholson, G. M. Stocks, Yang Wang, T. Dirks

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Massively parallel computers have been used to perform first principles spin dynamics (SD) simulations of the magnetic structure of γ-FeMn (iron-manganese). The code uses a novel parallel approach to solve the Kohn-Sham equations obtained from density functional theory (DFT). This approach uses limited local communications avoiding the large global communications found in other DFT based methods. This allows our code to scale efficiently to very large processor counts and large system sizes. Computationally our method can be implemented using mainly BLAS3 routines which typically run at a very high percentage of peak speed on most computers. Our large scale quantum mechanical simulations using this method reveal new details of the orientational configuration of the magnetic moments of γ-FeMn that are unobtainable by any other means. The understanding of the magnetic structure of γ-FeMn is important in exchange bias, which involves the use of an antiferromagnetic (AFM) layer such as FeMn to pin the orientation of the magnetic moment of a proximate ferromagnetic (FM). Exchange bias is of fundamental importance in magnetic multilayer storage and read head devices. Here the equation of motion of first principles SD is used to perform relaxations of model magnetic structures to the true ground (equilibrium) state. Our code has achieved a maximum execution rate of 2.46 teraflops on the IBM SP at the National Energy Research Scientific Computing Center (NERSC) and 4.65 teraflops on the HP-Compaq machine at the Pittsburgh Supercomputing Center (PSC).

Original languageEnglish
Title of host publicationProceedings - International Parallel and Distributed Processing Symposium, IPDPS 2003
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Electronic)0769519261, 9780769519265
DOIs
Publication statusPublished - Jan 1 2003
EventInternational Parallel and Distributed Processing Symposium, IPDPS 2003 - Nice, France
Duration: Apr 22 2003Apr 26 2003

Publication series

NameProceedings - International Parallel and Distributed Processing Symposium, IPDPS 2003

Other

OtherInternational Parallel and Distributed Processing Symposium, IPDPS 2003
CountryFrance
CityNice
Period4/22/034/26/03

    Fingerprint

ASJC Scopus subject areas

  • Computational Theory and Mathematics
  • Theoretical Computer Science
  • Software

Cite this

Canning, A., Ujfalussy, B., Schulthess, T. C., Zhang, X. G., Shelton, W. A., Nicholson, D. M. C., Stocks, G. M., Wang, Y., & Dirks, T. (2003). Parallel multi-teraflops studies of the magnetic structure of FeMn alloys. In Proceedings - International Parallel and Distributed Processing Symposium, IPDPS 2003 [1213465] (Proceedings - International Parallel and Distributed Processing Symposium, IPDPS 2003). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/IPDPS.2003.1213465