Altshuler-Aronov-Spivak oscillations of coherent bosonic matter-wave beams in the presence of interaction

We theoretically study the propagation of a guided atom laser across an Aharonov-Bohm ring
which is exposed to a synthetic gauge field. The presence of disorder within the ring gives rise to
Al’tshuler-Aronov-Spivak oscillations [1], seen in the disorder-averaged of the transmission as a function of the effective gauge flux that is contained within the ring. Those oscillations are induced by coherent backscattering and represent a manifestation of weak localisation. Through analytical and numerical calculations that are based on the mean-field Gross-Pitaevskii approximation for the propagating Bose-Einstein condensate, we show that the presence of a weak atom-atom interaction within the ring leads to an inversion of the Al’tshuler-Aronov-Spivak oscillations, in a very similar manner as for the coherent backscattering of Bose-Einstein condensates within two-dimensional disorder potentials [2]. Numerical simulations based on the Truncated Wigner method reveal that this signature of weak antilocalisation becomes washed out if the interaction strength is increased, which is in qualitative agreement with the findings of the diagrammatic study undertaken in Ref. [3].
[1] B. L. Al’tshuler, A. G. Aronov and B. Z. Spivak, JETP Lett. 33, 94 (1981).
[2] M. Hartung, T. Wellens, C. A. Müller, K. Richter, and P. Schlagheck, Phys. Rev. Lett. 101, 020603
(2008).
[3] T. Geiger, A. Buchleitner and T. Wellens, New J. Phys. 15, 115015 (2013).