Detecting quantum backflow by the density of a Bose-Einstein condensate Articles uri icon

publication date

  • May 2013

start page

  • 053618-1

end page

  • 053618-5


  • 5


  • 87

International Standard Serial Number (ISSN)

  • 1050-2947

Electronic International Standard Serial Number (EISSN)

  • 1094-1622


  • Quantum backflow is a classically forbidden effect consisting of a negative flux for states with negligible negative-momentum components. It has never been observed experimentally so far. We derive a general relation that connects backflow with a critical value of the particle density, paving the way for the detection of backflow by a density measurement. To this end, we propose an explicit scheme with Bose-Einstein condensates, at reach with current experimental technologies. Remarkably, the application of a positive-momentum kick, via a Bragg pulse, to a condensate with a positive velocity may cause a current flow in the negative direction.


  • Physics