| Journal: | Brazilian journal of physics |
| Database: | PERIÓDICA |
| System number: | 000403521 |
| ISSN: | 0103-9733 |
| Authors: | Pinto, A.C. Aguiar1 Moutinho, M1 Thomaz, M.T2 |
| Institutions: | 1Universidade Estadual de Mato Grosso do Sul, Dourados, Mato Grosso do Sul. Brasil 2Universidade Federal Fluminense, Instituto de Fisica, Niteroi, Rio de Janeiro. Brasil |
| Year: | 2009 |
| Season: | Jun |
| Volumen: | 39 |
| Number: | 2 |
| Pages: | 326-330 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Artículo |
| Approach: | Analítico |
| English abstract | We study the adiabatic evolution of a two-level model in the presence of an external classical electric field. The coupling between the quantum model and the classical field is taken in the electric dipole approximation. In this regime, we show the absence of geometric phases in the interacting two-level model in the presence of any periodic real time-dependent classical electric field. We obtain a conservative scalar potential in the calculation of Berry’s phases of the instantaneous eigenstates of the model. For complex electric fields, we recover the existence of geometric phases. In particular, the geometric phases of the instantaneous eigenstates of the model in the presence of a positive or of a negative frequency component of the monochromatic electric field differ by an overall sign. As a check on our results, we map this interacting two-level model onto a spin-1/2 model under the action of a classical magnetic field. We confirm that the first one acquires Berry’s phase only in the rotating wave approximation [RWA] |
| Disciplines: | Física y astronomía |
| Keyword: | Física de partículas y campos cuánticos, Fase de Berry, Teorema adiabático, Hamiltonianos, Campo eléctrico |
| Keyword: | Physics and astronomy, Particle physics and quantum fields, Berry phase, Adiabatic theorem, Hamiltonians, Electric field |
| Full text: | Texto completo (Ver PDF) |
