Nonlinear dynamics of a dense two-dimensional dipolar exciton gas

We propose a model for the nonlinear dynamics of a dense two dimensional dipolar exciton gas. The model predicts an initial fast expansion due to a dipole-dipole pressure, followed by a much slower diffusion. The model is with a very good agreement with recent experimental results. We show that the dipole pressure induced expansion strongly constrains the time available for achieving and observing Bose-Einstein quantum statistical effects, indicating a need for spatial exciton traps. We also suggest that a nonlinear ballistic exciton transport due to the strong internal dipole pressure is readily achievable.