I have finished processing a batch and built the first magnetic phase diagram last week, based on our computation.
The main difficulty (why the data took so long to process and why there still might be some glitches in the dataset) was posed by "bad" data points. These points correspond to the results, returned by faulty computers. Their recalculation on a different PC produces the correct answers, but the main difficulty was finding (manually) -- which points to recalculate. By now, I hope to have found most of these points, influencing the phase diagram below. But the data set will have to be recalculated with enabled BOINC redundancy (sending the same workunit to two hosts at least and comparing the result). I've started this run of the project today.
Another problem, solved by the new run, is that now the whole range of particle's aspect ratios is covered uniformly, something I have overlooked, submitting the first batch.
Now, the ground states:
This is the raw map, showing the values of aspect ratios, which have actually been calculated (non-uniform coverage and the gap in the bottom is the result of the second of the previously mentioned problems). The vertical coordinate on the plot is the cylinder's radius, divided by the material's exchange length. The horisontal is thickness, divided by the exchange length. The range of vertical and horizontal coordinates is from 0 to 5 (which is about 100nm for Permalloy).
This is the close up of the origin of the diagram.
This is the same diagram, but with spline interpolation across the aspect ratios. The waviness of the orange/yellow boundary at the bottom is, probably, due to another set of "bad" points I could not find yet and should be fixed by the new batch.
The colors of the regions correspond to different magnetization ground states. You can see sketches and names of these states in the slideshow inside your BOINC client if you switch it to the "simple view".
There are many interesting features on this diagram I'd rather spend time discussing in the paper, but if you ask the right questions I'll be glad to explain it here as well.
The data set we have calculated contains much more than this diagram, it also contains the metastable states and the energy barriers between them, but that will be the subject of future work. The new picture of ground states (above) is surprising enough to publish it separately.
OK. Now your questons. ;-)
PLEASE NOTE: the above pictures are shown here on the same basis as "preprint". They are part of the forthcoming and developing scientific paper. Please contact me for an updated reference to this work, if you need it.