About Magnetism@home
Magnetism@home is a research project that uses Internet-connected
computers to explore the equlibrium, metastable and transient magnetization
patterns (first and foremost in nano-scale magnetic elements and their arrays,
but later other systems may be considered).
You can participate by downloading and running a free program on your
computer.
The project is based at Donetsk Institute for Physics and Technology.
To understand scientific side of things:
- Please see this preprint
(latest and the most complete in this series of works) and references therein.
- In this project we evaluate numerically the total
(exchange + magnetostatic) energy of these magnetization distributions
(using finite elements and a special "thin film" variant of
fast multipole method)
with the aim to minimize this energy numerically to build maps of ground and
metastable states in magnetic nano-elements of various shapes.
- The source code is
here.
- Currently the program demonstrated sufficient precision for building the
map of ground states. Improving its precision for resolving the
metastable states is in progress.
Join Magnetism@home
Returning participants
Community
|
User of the day
redchuk
|
News
Data release 1.
Oct 8, 2012
There are, actually, new and exciting things in the data we have computed ! I have prepared a paper on this, which is currently being submitted for publication. This paper references as supplemental material the computed data, which I'm releasing now as Magnetism@home data release 1 (or here). More details are in the README file of the archive. The paper itself will be available later, as soon as it passes review.
Metastable states.
Sep 11, 2011
The last run with antialiasing had enough precision to resolve (at least some of) the metastable states. In particular, it allows to build the region of existence of metastable vortices: map_0.5, map_1.0, map_1.5. These three maps correspond to different comparison tolerances (in percents) in the algorithm for metastable state detection (the lower barriers are considered passable). As one can see, the dependence on the tolerance in most regions on the map is rather small to make it sound. This result is new, because the boundary does not completely fit any of the known partial results for the vortex stability line. Right now I'm working on analytical model to supplement this numerical map. There will be no new WUs for some time, probably. This is because in the light of the new developments in the underlying theory the program will have to be significantly modified, to cover much wider array of cases. (moreover, there are even further developments, which I'm readying for publication right now). But, even if there are no new WUs for a while, please consider the project alive. Numerical calculations constitute only a part of it, the smaller part.
Server upgrade.
Aug 29, 2010
I've just moved our WWW server (including BOINC) to a new virtual machine. It is possible that something was overlooked in the process. Please tell, if some features of the site do not work anymore. Otherwise I'm back from vacations and soon will start processing the results of our last run.
Another batch, now with anti-aliasing.
May 13, 2010
The previous run have reproduced the map of ground states in circular nano-cylinder in agreement with theory (which means that the energy is calculated correctly), but its precision was not enough to obtain the map of metastable states. This is because tracing of metastable states involves taking derivatives, which amplifies the errors. To reduce the jitter, associated with assignment of constant charges to finite elements, I have introduced a Monte-Carlo anti-aliasing procedure to calculate the average density of charges across each finite element. I hope this will be sufficient to reduce the jitter. We'll see. If not, there are other, more intensive methods.
New batch of workunits.
November 24, 2008
After finishing processing the previous batch I have launched a new one today. New workunits require about 330 Mb of RAM to complete, which should not be that much. A summary of the preliminary results of the previous run is here.
...more
News is available as an
RSS feed .
|