Landau-Zener tunneling in a nonlinear three-level system

Journal Article · Fri Sep 15 04:00:00 EDT 2006 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.74.033414· OSTI ID:20857727

Guanfang, Wang ^[1]; Difa, Ye; Libin, Fu; Jie, Liu ^[1]; Xuzong, Chen ^[2]

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1. Institute of Applied Physics and Computational Mathematics, P.O. Box 8009 (28), 100088 Beijing (China)
2. Key Laboratory for Quantum Information and Measurements, Ministry of Education, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China)

We present a comprehensive analysis of the Landau-Zener tunneling of a nonlinear three-level system in a linearly sweeping external field. We find the presence of nonzero tunneling probability in the adiabatic limit (i.e., very slowly sweeping field) even for the situation that the nonlinear term is very small and the energy levels keep the same topological structure as that of the linear case. In particular, the tunneling is irregular with showing an unresolved sensitivity on the sweeping rate. For the case of fast-sweeping fields, we derive an analytic expression for the tunneling probability with stationary phase approximation and show that the nonlinearity can dramatically influence the tunneling probability when the nonlinear 'internal field' resonate with the external field. We also discuss the asymmetry of the tunneling probability induced by the nonlinearity. Physics behind the above phenomena is revealed and possible application of our model to triple-well trapped Bose-Einstein condensate is discussed.

• OSTI ID: 20857727
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 3 Vol. 74; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
APPROXIMATIONS
ASYMMETRY
BOSE-EINSTEIN CONDENSATION
ENERGY LEVELS
LANDAU-ZENER FORMULA
NONLINEAR PROBLEMS
PROBABILITY
SENSITIVITY
TOPOLOGY
TRAPPING
TUNNEL EFFECT