Nonextensive approach to decoherence in quantum mechanics
  We propose a nonextensive generalization (q parametrized) of the von Neumann equation for the density operator. Our model naturally leads to the phenomenon of decoherence, and unitary evolution is recovered in the limit of q -> 1. The resulting evolution yields a nonexponential decay for quantum coherences, fact that might be attributed to nonextensivity. We discuss, as an example, the loss of coherence observed in trapped ions. 
A. Vidiella-Barranco and H. Moya-Cessa (INAOE, Puebla, Pue., Mexico)