Decay of Loschmidt echo in a Bose-Einstein condensate at a dynamical phase transition

Journal Article · Wed Jul 15 00:00:00 EDT 2009 · Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print)

DOI:https://doi.org/10.1103/PHYSREVE.80.016214· OSTI ID:21294247

Qiang, Zheng ^[1]; Wenge, Wang; Pinquan, Qin; Ping, Wang ^[2]; Xiaoping, Zhang; Zhongzhou, Ren ^[1]

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1. Department of Physics, Nanjing University, Nanjing 210093 (China)
2. Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)

We study the quantum Loschmidt echo (LE) in a Bose-Einstein condensate (BEC) in a double-well potential. The BEC may undergo a dynamical phase transition between two phases: a tunneling phase and a self-trapping phase. For sufficiently weak perturbation, the LE has Gaussian decay in both phases. While, for relatively strong perturbation, the LE has a Gaussian decay in the self-trapping phase and has a stretched exponential decay in the tunneling phase. This qualitative difference in the decaying law of the LE in the two phases provides a characterization of the dynamical phase transition of the BEC. The semiclassical theory is used to explain the numerically observed behaviors of the LE decay.

• OSTI ID: 21294247
• Journal Information: Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics (Print), Vol. 80, Issue 1; Other Information: DOI: 10.1103/PhysRevE.80.016214; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1539-3755
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOSE-EINSTEIN CONDENSATION
PERTURBATION THEORY
PHASE TRANSFORMATIONS
SEMICLASSICAL APPROXIMATION
TUNNEL EFFECT