Periodic instanton method and macroscopic quantum tunneling between two weakly-linked Bose-Einstein condensates

Abstract

A new method is used to investigate the tunneling between two weakly-linked Bose-Einstein condensates confined in double-well potential traps. The nonlinear interaction between the atoms in each well contributes to a finite chemical potential, which, with consideration of periodic instantons, leads to a remarkably high tunneling frequency. This result can be used to interpret the newly found Macroscopic Quantum Self Trapping (MQST) effect. Also a new kind of first-order crossover between different regions is predicted.

4 pages, 2 eps figures, final version to appear in Phys. Rev. A