Superfluid current disruption in a chain of weakly coupled Bose–Einsteincondensates

Abstract

Listen

Translate article

We report the experimental observation of the disruption of the superfluid atomiccurrent flowing through an array of weakly linked Bose–Einstein condensates. Thecondensates are trapped in an optical lattice superimposed on a harmonicmagnetic potential. The dynamical response of the system to a change of themagnetic potential minimum along the optical lattice axis goes from a coherentoscillation (superfluid regime) to a localization of the condensates in theharmonic trap (‘classical’ insulator regime). The localization occurs whenthe initial displacement is larger than a critical value or, equivalently,when the velocity of the wavepacket’s centre of mass is larger than acritical velocity dependent on the rate of tunnelling between adjacent sites.