| Journal: | Brazilian journal of physics |
| Database: | PERIÓDICA |
| System number: | 000335826 |
| ISSN: | 0103-9733 |
| Authors: | Dartora, C.A1 Cabrerat, G.G2 Nobrega, K.Z3 |
| Institutions: | 1Universidade Federal do Parana, Departamento de Engenharia Eletrica, Curitiba, Parana. Brasil 2Universidade Estadual de Campinas, Instituto de Fisica "Gleb Wataghin", Campinas, Sao Paulo. Brasil 3CEFET, Departamento de Energia Eletrica, Sao Luis, Maranhao. Brasil |
| Year: | 2009 |
| Season: | Sep |
| Volumen: | 39 |
| Number: | 3 |
| Pages: | 587-591 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Experimental, analítico |
| English abstract | The description of quantum dynamics of nanomagnets is a central issue in most applications proposed for those systems. In this paper, we put forward a modified perturbation approach to study the spin dynamics of a molecular magnet in the presence of time-dependent magnetic fields.The non-perturbed Hamiltonian H0, which defines the interaction picture, may be time-dependent proviso it can be diagonalized at all times by the same basis of states. We probe the method using a simple model Hamiltonian, that contains the important anisotropy terms relevant for Fe8 molecular clusters, and solve as an example the case with the smallest non trivial spin value (S=1). Our modified perturbation approach converges rapidly to the exact solution, goes beyond the Kubo linear response theory, and is well defined even at resonance. Temperature effects in the spin dynamics are taken into account in the context of the density matrix |
| Disciplines: | Física y astronomía |
| Keyword: | Física atómica y molecular, Dinámica cuántica, Nanomagnetos, Dinámica de espín, Teoría de perturbaciones |
| Keyword: | Physics and astronomy, Atomic and molecular physics, Quantum dynamics, Nanomagnets, Spin dynamics, Perturbation theory |
| Full text: | Texto completo (Ver HTML) |
