Show simple item record

dc.contributorVirginia Tech
dc.contributor.authorYamamoto, Y.
dc.contributor.authorPark, K.
dc.date.accessioned2014-01-17T13:41:35Z
dc.date.available2014-01-17T13:41:35Z
dc.date.issued2013-07-11
dc.identifier.citationYamamoto, Yoh ; Park, Kyungwha, Jul 11, 2013. "Metastability for the Blume-Capel model with distribution of magnetic anisotropy using different dynamics," PHYSICAL REVIEW E 88(1): 012110. DOI: 10.1103/PhysRevE.88.012110
dc.identifier.issn1539-3755
dc.identifier.urihttp://hdl.handle.net/10919/24902
dc.description.abstractWe investigate the relaxation time of magnetization or the lifetime of the metastable state for a spin S = 1 square-lattice ferromagnetic Blume-Capel model with distribution of magnetic anisotropy (with small variances), using two different dynamics such as Glauber and phonon-assisted dynamics. At each lattice site, the Blume-Capel model allows three spin projections (+1, 0, -1) and a site-dependent magnetic anisotropy parameter. For each dynamic, we examine the low-temperature lifetime in two dynamic regions with different sizes of the critical droplet and at the boundary between the regions, within the single-droplet regime. We compute the average lifetime of the metastable state for a fixed lattice size, using both kinetic Monte Carlo simulations and the absorbing Markov chains method in the zero-temperature limit. We find that for both dynamics the lifetime obeys a modified Arrhenius-like law, where the energy barrier of the metastable state depends on the temperature and standard deviation of the distribution of magnetic anisotropy for a given field and magnetic anisotropy and that an explicit form of this dependence differs in different dynamic regions for different dynamics. Interestingly, the phonon-assisted dynamic prevents transitions between degenerate states, which results in a large increase in the energy barrier at the region boundary compared to that for the Glauber dynamic. However, the introduction of a small distribution of magnetic anisotropy allows the spin system to relax via lower-energy pathways such that the energy barrier greatly decreases. In addition, for the phonon-assisted dynamic, even the prefactor of the lifetime is substantially reduced for a broad distribution of magnetic anisotropy in both regions considered, in contrast to the Glauber dynamic. Our findings show that overall the phonon-assisted dynamic is more significantly affected by the distribution of magnetic anisotropy than the Glauber dynamic.
dc.description.sponsorshipNSF DMR-0804665, DMR-1206354
dc.language.isoen_US
dc.publisherAmerican Physical Society
dc.subjectkinetic ising-model
dc.subjectfept nanoparticles
dc.subjectsystems
dc.subjectfield
dc.subjectspin
dc.subjectrelaxation
dc.subjectnucleation
dc.subjectdependence
dc.subjectconstant
dc.subjectlattice
dc.subjectPhysics
dc.titleMetastability for the Blume-Capel model with distribution of magnetic anisotropy using different dynamics
dc.typeArticle
dc.identifier.urlhttp://link.aps.org/doi/10.1103/PhysRevE.88.012110
dc.date.accessed2013-12-17
dc.title.serialPhysical Review E
dc.identifier.doihttps://doi.org/10.1103/PhysRevE.88.012110


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record