Collisions of anisotropic two-dimensional bright solitons in dipolar   Bose-Einstein condensates
  We investigate the coherent collision of anisotropic quasi-two-dimensional bright solitons in dipolar Bose-Einstein condensates. Our analysis is based on the extended Gross-Pitaevskii equation, and we use the split-operator method for the grid calculations and the time-dependent variational principle with an ansatz of coupled Gaussian functions to calculate the time evolution of the ground state. We compare the results of both approaches for collisions where initially the solitons are in the repelling side-by-side configuration and move towards each other with a specific momentum. We change the relative phases of the condensates, and introduce a total angular momentum by shifting the solitons in opposite direction along the polarization axis. Our calculations show that collisions result in breathing-mode-like excitations of the solitons. 
R\"udiger Eichler, Damir Zajec, Patrick K\"oberle, J\"org Main,   G\"unter Wunner
cond-mat.quant-gas quant-ph