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Bruno M. Miranda

Publications and source records attributed to Bruno M. Miranda.

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Dynamics of localized solutions in three core coupled waveguides with quasi-periodic nonlinearity

In this paper we investigate the behavior of localized solutions, specifically solitons, in a system of three coupled waveguides. The nonlinearity is modeled by a quasi-periodic modulation influencing the interaction between the waveguides. We analyze the evolution of the soliton profiles and their dynamics under varying modulation parameters, highlighting distinct behaviors such as attraction and repulsion among solitons. Our findings reveal that the system exhibits complex behaviors, depending on the interplay between the quasi-periodic modulation and the waveguide parameters. The study contributes to understanding the impact of quasi-periodic nonlinearity on soliton dynamics in coupled waveguide systems, laying the groundwork for potential applications in nonlinear optics and photonic devices.

nlin.PS

Symmetry Breaking in Bose-Einstein Condensates Confined by a Funnel Potential

In this work, we consider a Bose-Einstein condensate in the self-focusing regime, confined transversely by a funnel-like potential and axially by a double-well potential formed by the combination of two inverted Pöschl-Teller potentials. The system is well described by a one-dimensional nonpolynomial Schrödinger equation, for which we analyze the symmetry break of the wave function that describes the particle distribution of the condensate. The symmetry break was observed for several interaction strength values as a function of the minimum potential well. A quantum phase diagram was obtained, in which it is possible to recognize the three phases of the system, namely, symmetric phase (Josephson), asymmetric phase (spontaneous symmetry breaking - SSB), and collapsed states, i.e., those states for which the solution becomes singular, representing unstable solutions for the system. We analyzed our symmetric and asymmetric solutions using a real-time evolution method, in which it was possible to confirm the stability of the results. Finally, a comparison with the cubic nonlinear Schrödinger equation and the full Gross-Pitaevskii equation were performed to check the accuracy of the effective equation used here.

cond-mat.quant-gas