Statistical electron excitation in a double quantum dot induced by two   independent quantum point contacts
  We investigate experimentally the influence of current flow through two independent quantum point contacts to a nearby double quantum dot realized in a GaAs-AlGaAs heterostructure. The observed current through the double quantum dot can be explained in terms of coupling to a bosonic bath. The temperature of the bath depends on the power generated by the current flow through the quantum point contact. We identify the dominant absorption and emission mechanisms in a double quantum dot as an interaction with acoustic phonons. The experiment excludes coupling of a double quantum dot to shot noise generated by quantum point contact as the dominant mechanism. 
U. Gasser, S. Gustavsson, B. K\"ung, K. Ensslin, T. Ihn, D.C.   Driscoll, A.C. Gossard