Bose-Einstein condensation at constant temperature
  We present a novel experimental approach to Bose-Einstein condensation by increasing the particle number of the system at almost constant temperature. In particular the emergence of a new condensate is observed in multi-component F=1 spinor condensates of 87-Rb. Furthermore we develop a simple rate-equation model for multi-component BEC thermodynamics at finite temperature which well reproduces the measured effects. 
M. Erhard, H. Schmaljohann, J. Kronj\"ager, K. Bongs, K. Sengstock