Enhanced backscattering of a dilute Bose-Einstein condensate

¹ Institut Non Linéaire de Nice, UMR 7335, UNS, CNRS - 1361 route des Lucioles, F-06560 Valbonne, France, EU
² Center for Quantum Technologies, National University of Singapore - 3 Science Drive 2, Singapore 117543, Singapore
³ Wydział Fizyki, Uniwersytet w Białymstoku - ul. Lipowa 41, 15-424 Białystok, Poland, EU
⁴ Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien - 1020 Vienna, Austria, EU
⁵ Department of Physics, National University of Singapore - 2 Science Drive 3, Singapore 117543, Singapore
⁶ Laboratoire Kastler Brossel, Ecole Normale Supérieure, CNRS, UPMC - 4 Place Jussieu, F-75005 Paris, France, EU

Received: 30 November 2012
Accepted: 2 December 2012

Abstract

We study experimentally and numerically the quasi-bidimensional transport of a ⁸⁷Rb Bose-Einstein condensate launched with a velocity v₀ inside a disordered optical potential created by a speckle pattern. A time-of-flight analysis reveals a pronounced enhanced density peak in the backscattering direction −v₀, a feature reminiscent of coherent backscattering. Detailed numerical simulations indicate, however, that other effects also contribute to this enhancement, including a “backscattering echo” due to the position-momentum correlations of the initial wave packet.