Coherent backscattering in Fock space: a signature of quantum many-body interference in interacting bosonic systems.
We predict a generic signature of quantum interference in many-body bosonic systems resulting in a coherent enhancement of the average return probability in Fock space. This enhancement is robust with respect to variations of external parameters even though it represents a dynamical manifestation of the delicate superposition principle in Fock space. It is a genuine quantum many-body effect that lies beyond the reach of any mean-field approach. Using a semiclassical approach based on interfering paths in Fock space, we calculate the magnitude of the backscattering peak and its dependence on gauge fields that break time-reversal invariance. We confirm our predictions by comparing them to exact quantum evolution probabilities in Bose-Hubbard models, and discuss their relevance in the context of many-body thermalization.
Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg, Germany.
Thomas
T
Engl
Département de Physique, University of Liege, 4000 Liège, Belgium.
Julien
J
Dujardin
Département de Physique, University of Liege, 4000 Liège, Belgium.
Arturo
A
Argüelles
Département de Physique, University of Liege, 4000 Liège, Belgium.
Peter
P
Schlagheck
Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg, Germany.
Klaus
K
Richter
Institut für Theoretische Physik, Universität Regensburg, D-93040 Regensburg, Germany.
Juan Diego
JD
Urbina