Estabilidade de sistemas condensados com interação atrativa ou repulsiva

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Exotic Bose-Einstein condensates: binary mixtures and dipolar gases

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dinâmica das transições quiral e de desconfinamento da cromodinâmica quântica com o modelo Polyakov-Nambu-Jona-Lasinio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação do gradiente de pH na região interna a duas membranas em equilíbrio com eletrólito

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Amphiphilic planar membranes in ionic equilibrium: a study of pH position-dependent values

The pH values near a planar dissociating membrane are studied under a mean field approximation using the Poisson-Boltzmann equation and its linear form. The equations are solved in planar symmetry with the consideration that the charge density on the dissociating membrane surface results from an equilibrium process with the neighboring electrolyte. Results for the membrane dissociation degree are presented as a function of the electrolyte ionic strength and membrane surface charge density. Our calculations indicate that pH values have an appreciable variation within 2 nm from the membrane. It is shown that the dissociation process is enhanced due to the presence of bivalent ions and that pH values acquire better stability than in an electrolyte containing univalent ions.

Excitonic instabilities and spontaneous time-reversal symmetry breaking on the honeycomb lattice

We elucidate the close relationship between spontaneous time-reversal symmetry breaking and the physics of excitonic instabilities in strongly correlated multiband systems. The underlying mechanism responsible for the spontaneous breaking of time-reversal symmetry in a many-body system is closely related to the Cooper-like pairing instability of interband particle-hole pairs involving higher-order symmetries. Studies of such pairing instabilities have, however, mainly focused on the mean-field aspects of the virtual exciton condensate, which ignores the presence of the underlying collective Fermi-liquid excitations. We show that this relationship can be exploited to systematically derive the coupling of the condensate order parameter to the intraband Fermi-liquid particle-hole excitations. Surprisingly, we find that the static susceptibility is negative in the ordered phase when the coupling to the Fermi-liquid collective excitations are included, suggesting that a uniform condensate of virtual excitons, with or without time-reversal breaking, is an unstable phase at T = 0.

Self-trapping of a dipolar Bose-Einstein condensate in a double well

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Simplified pure spinor b ghost in a curved heterotic superstring background

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A construction of integrated vertex operator in the pure spinor sigma-model in AdS(5) x S-5

Vertex operators in string theory me in two varieties: integrated and unintegrated. Understanding both types is important for the calculation of the string theory amplitudes. The relation between them is a descent procedure typically involving the b-ghost. In the pure spinor formalism vertex operators can be identified as cohomology classes of an infinite-dimensional Lie superalgebra formed by covariant derivatives. We show that in this language the construction of the integrated vertex from an unintegrated vertex is very straightforward, and amounts to the evaluation of the cocycle on the generalized Lax currents.

Bright solitons in a quasi-one-dimensional reduced model of a dipolar Bose-Einstein condensate with repulsive short-range interactions

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Statics and dynamics of a binary dipolar Bose-Einstein condensate soliton

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Landscape Diversity Influences Dispersal and Establishment of Pest with Complex Nutritional Ecology

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Multikink solutions and deformed defects

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Orbit based procedure for doublets of scalar fields and the emergence of triple kinks and other defects

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bright dipolar Bose-Einstein-condensate soliton mobile in a direction perpendicular to polarization

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)