Instability of collective excitations and power laws of an attractive Bose-Einstein condensate in an anharmonic trap

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.82.043614· OSTI ID:21450835

Debnath, P K ^[1]; Chakrabarti, Barnali ^[2]

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1. Santoshpur Sri Gouranga Vidyapith (H.S.), P.O. Kulitapara, Howrah 711312 (India)
2. Department of Physics, Lady Brabourne College, P1/ 2 Surawardi Avenue, Kolkata 700017 (India)

We study the instability of collective excitations of a three-dimensional Bose-Einstein condensate with repulsive and attractive interactions in a shallow trap designed as a quadratic plus a quartic potential. By using a correlated many-body theory, we determine the excitation modes and probe the critical behavior of collective modes, having a crucial dependence on the anharmonic parameter. We examine the power-law behavior of monopole frequency near criticality. In Gross-Pitaevskii variational treatment [Phys. Rev. Lett. 80, 1576 (1998)] the power-law exponent is determined as one-fourth power of (1-(A/A{sub cr})), A is the number of condensate atoms and A{sub cr} is the critical number near collapse. We observe that the power-law exponent becomes (1/6) in our calculation for the pure harmonic trap and it becomes (1/7), for traps with a small anharmonic distortion. However for large anharmonicity the power law breaks down.

• OSTI ID: 21450835
• Journal Information: Physical Review. A, Vol. 82, Issue 4; Other Information: DOI: 10.1103/PhysRevA.82.043614; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BOSE-EINSTEIN CONDENSATION
COLLECTIVE EXCITATIONS
INSTABILITY
MANY-BODY PROBLEM
MONOPOLES
POTENTIALS
THREE-DIMENSIONAL CALCULATIONS
TRAPS
VARIATIONAL METHODS
CALCULATION METHODS
ENERGY-LEVEL TRANSITIONS
EXCITATION