Electrostatic traps for dipolar excitons
  We consider the design of two-dimensional electrostatic traps for dipolar indirect excitons. We show that the excitons dipole-dipole interaction, combined with the in-plane electric fields that arise due to the trap geometry, constrain the maximal density and lifetime of trapped excitons. We derive an analytic estimate of these values and determine their dependence on the trap geometry, thus suggesting the optimal design for high density trapping as a route for observing excitonic Bose-Einstein condensation. 
Ronen Rapaport, Gang Chen, Steve Simon, Oleg Mitrofanov, Loren   Pfeiffer, P. M. Platzman