Coupling between Topological Excitations and the Background Sound Field in Atomic Bose-Einstein Condensates

Abstract

Topological excitations in quantum fluids are coupled to the background sound field. This leads to a continuous exchange of energy between the two systems, as a result of which, the topological excitation can become deformed and its trajectory modified. These effects are considered in detail for dark solitons in trapped one-dimensional atomic Bose-Einstein condensates. The energy emitted by the dark soliton incident on a background potential gradient is shown to be proportional to the square of both the soliton deformation and the local soliton acceleration. Depending on the trap geometry, this energy can be partly or fully reabsorbed by the soliton, thus affecting its stability. The extensi..