Modulational instability in addition to discrete breathers in 2D quantum ultracold atoms loaded in optical lattices

• Published in: Nonlinear dynamics Vol. 98; no. 3; pp. 1905 - 1918
• Main Authors: Djoufack, Z. I., Fotsa-Ngaffo, F., Tala-Tebue, E., Fendzi-Donfack, E., Kapche-Tagne, F.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-11-2019; Springer Nature B.V
• Subjects: Approximation; Automotive Engineering; Breathers; Brillouin zones; Classical Mechanics; Control; Dynamical Systems; Engineering; Interaction parameters; Mechanical Engineering; Optical lattices; Original Paper; Stability; Stability analysis; Ultracold atoms; Vibration; Modulational instability; Optical lattice; Discrete breathers; Quantum ultracold atoms
• ISSN: 0924-090X; 1573-269X
• DOI: 10.1007/s11071-019-05295-w

The modulational instability associated with discrete breathers in 2D quantum ultracold atoms is studied by using the Glauber’s coherent state combined with a semi-discrete approximation and multiple-scale methods. The linear stability analysis exhibits an intriguing threshold amplitude and instability regions associated with modulational growth rate. In addition, we demonstrate a coexistence of two bright intrinsic localized modes namely, the radial symmetric and bilateral symmetric modes, at the center and at the edges of the Brillouin zone, respectively, by alternating the on-site parameter interaction. Numerical investigations reveal a good agreement with the theoretical analysis.