  We investigated the tunnelling dynamics of a zero-temperature Bose-Einstein
condensate (BEC) in configuration of four potential wells arranged in a loop.
We found three interesting dynamic regimes: (a) flows of matter with small
amplitude, (b) steady flow and (c) forced flow of matter for large amplitudes.
The regime of quantum self-confinement has been studied and a new variant of it
has been found for this system.
