Condensation of bosons with several degrees of freedom
The condensation of the spinless ideal charged Bose gas in the presence of a magnetic field is revisited as a first step to tackle the more complex case of a molecular condensate, where several degrees of freedom have to be taken into account. In the charged bose gas, the conventional approach is ex...
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| Tipo de recurso: | tesis de maestría |
| Fecha de publicación: | 2013 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/36384 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/36384 |
| Access Level: | acceso abierto |
| Palabra clave: | 538.9 Statistical Mechanics Macrocanonical Ensemble Bose Einstein Condensation Density of States Degenerate Matter Bogoliubov Interactions Mecánica Estadística Distribución Macrocanónica Condensación de Bose Einstein Densidad de Estados Materia Degenerada Interacciones de Bogoliubov Física de materiales |
| Sumario: | The condensation of the spinless ideal charged Bose gas in the presence of a magnetic field is revisited as a first step to tackle the more complex case of a molecular condensate, where several degrees of freedom have to be taken into account. In the charged bose gas, the conventional approach is extended to include the macroscopic occupation of excited kinetic states lying in the lowest Landau level, which plays an essential role in the case of large magnetic fields. In that limit, signatures of two diffuse phase transitions (crossovers) appear in the specific heat. In particular, at temperatures lower than the cyclotron frequency, the system behaves as an effectively one-dimensional free boson system, with the specific heat equal to (1/2) NkB and a gradual condensation at lower temperatures. In the molecular case, which is currently in progress, we have studied the condensation of rotational levels in a two–dimensional trap within the Bogoliubov approximation, showing that multi–step condensation also occurs. |
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