Bose Einstein Condensation
Mostrando 25-36 de 36 artigos, teses e dissertações.
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25. Some unusual algebraic structures and their applications in many-body problems
In this paper, we introduce the q-deformed and quon algebras formalism. Some applications of these algebraic structures are considered. A possible connection of the quon algebra with composite particle systems is discussed and perspectives on using such mathematical objects in the Bose-Einstein condensation is presented.
Brazilian Journal of Physics. Publicado em: 2003-06
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26. Experimental development to produce and study quantum gases: Bose-Einstein condensation / Desenvolvimento experimental para produção e estudo de gases quânticos: condensação de Bose-Einstein
We present here all the experimental development obtained in São Carlos to produce and study quantum degenerate gases, aiming specially the realization of Bose-Einstein Condensation (BEC) in sodium (Na-23) atoms. In order to do that we designed, built and completely integrated a complex experimental setup which conjugates most of the techniques developed al
Publicado em: 2002
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27. Note on BEC in Nonextensive Statistical Mechanics
The generalized Bose-Einstein distribution, within the dilute gas assumption, in the nonextensive Tsallis statistics is worked without approximation for the Bose-Einstein condensation (BEC). The results obtained are compared with the recent results presented in Int. J. Mod. Phys. B 14, 405 (2000) by L. Salasnich. Furthermore, in order to promote a complete a
Brazilian Journal of Physics. Publicado em: 2001-06
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28. Bose-Einstein condensation in a constant magnetic field
We discuss the occurrence of Bose-Einstein condensation in systems of noninteracting charged particles in three and one dimensions and in presence of an external magnetic field. In the one dimensional, as well as in the magnetic field cases, although not a critical temperature, a characteristic temperature can be found, corresponding to the case in which the
Brazilian Journal of Physics. Publicado em: 2000-06
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29. Complexidade em sistemas dinamicos : formalismo termodinamica e mecanico estatistico
We present a Statistical Mechanics for nonlinear systems and a Thermodynamics of irreversible processes capable to deal with the so-called complex systems. Two powerful approaches have been used, namely - Predictive Statistical Mechanics -based on Information Theory -in what consists of the Nonequilibrium Ensemble Formalism (NESOM), and Zubarev s approach is
Publicado em: 1998
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30. Efeitos não-lineares em sistemas dissipativos
A non-linear quantum transport theory for many-body systems arbitrarily away from equilibrium is elaborated using Zubarev s non-equilibrium statistical operator method. It is described an iterative method that allows to organize the collision integrals with memory in a series of partial contribution of increasing power in the intensity of the interaction, le
Publicado em: 1991
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31. Effects of confinement in a magnetized Bose gas. / Efeitos de confinamento em um gás de bósons magnetizado.
São investigadas, utilizando-se a distribuição grande canônica, as modificações introduzidas nas propriedades termodinâmicas e magnéticas de um sistema de bosons confinado por um potencial harmônico cilindricamente e esfericamente simétrico. O sistema apresenta condensação de B.E. somente no limite de confinamento fraco e a causa desta transiçã
Publicado em: 1978
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32. Efeitos de uma impureza delta-atrativa nas propriedades termodinâmicas de um gás ideal de Bose em uma dimensão. / One dimensional Bose-Einstein condensation due to an atractive delta impurity center
Neste trabalho é estudado o comportamento termodinâmico de um gás unidimensional de bosons sob a ação de uma impureza delta atrativa. O sistema apresenta o fenômeno da condensação de Bose- Einstein e a causa da transição é atribuida ao estado ligado introduzido pela impureza no espectro de partícula livre. A fase condensada é composta pelas part
Publicado em: 1976
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33. Bose–Einstein condensation
The National Academy of Sciences of the USA.
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34. Polariton lasing vs. photon lasing in a semiconductor microcavity
Nearly one decade after the first observation of Bose–Einstein condensation in atom vapors and realization of matter-wave (atom) lasers, similar concepts have been demonstrated recently for polaritons: half-matter, half-light quasiparticles in semiconductor microcavities. The half-light nature of polaritons makes polariton lasers promising as a new source
National Academy of Sciences.
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35. Gravitational vacuum condensate stars
A new final state of gravitational collapse is proposed. By extending the concept of Bose–Einstein condensation to gravitational systems, a cold, dark, compact object with an interior de Sitter condensate pv = -ρv and an exterior Schwarzschild geometry of arbitrary total mass M is constructed. These regions are separated by a shell with a small but finite
National Academy of Sciences.
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36. Design for an optical cw atom laser
A new type of optical cw atom laser design is proposed that should operate at high intensity and high coherence and possibly record low temperatures. It is based on an “optical-shepherd” technique, in which far-off-resonance blue-detuned swept sheet laser beams are used to make new types of high-density traps, atom waveguides, and other components for ac
National Academy of Sciences.