Eur. Phys. J. D 44, 537-540 (2007)
https://doi.org/10.1140/epjd/e2007-00224-4

Quantum dynamics of bosons in a double-well potential: Josephson oscillations, self-trapping and ultralong tunneling times

¹ Instituto de Física, Universidade de São Paulo, CP 66318 CEP, 05389-970 São Paulo, SP, Brazil
² Departamento de Física, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, CP 702, CEP, 30161-970 Belo Horizonte, Minas Gerais, Brazil
³ Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany

Corresponding author: ^a andreans@fma.if.usp.br

Received: 5 February 2007
Published online: 29 June 2007

Abstract

The dynamics of the population imbalance of bosons in a double-well potential is investigated from the point of view of many-body quantum mechanics in the framework of the two-mode model. 
 For small initial population imbalances, coherent superpositions of almost equally spaced energy eigenstates lead to Josephson oscillations. The suppression of tunneling at population imbalances beyond a critical value is related to a high concentration of initial state population in the region of the energy spectrum with quasi-degenerate doublets. Negligible coherences among adjacent doublets result in imbalance oscillations with a very small amplitude. For unaccessible long times, however, the system recovers the regime of Josephson oscillations.