We study the transition probability and coherence of a charge tunneling between two states and interacting with an oscillator [1]. Both properties depend on the initial preparation in which the oscillator is in a thermal state. We show that a non dissipative evolution of a tunneling system strongly coupled to a single oscillator can give rise to decoherence phenomena when the initial distribution of the oscillator is thermal and when the oscillator distribution is not initially equilibrated in the presence of the charge, i.e. when it is sufficiently far from the thermal equilibrium distribution in the presence of the charge [2]. These decoherence phenomena are thus independent of the presence of an external bath which may eventually prevent asymptotic recoherence. If time allows I will also discuss extension of the present treatement to more realistic models for nanoscopic systems [3].

[1] S. Paganelli S. Ciuchi J. Phys.: Condens. Matter 18 7669-7685 (2006). [2] S. Paganelli S. Ciuchi J. Phys.: Condens. Matter 20 235203 (2008) [3] I. N. Hulea , S. Fratini, H. Xie, C.L. Mulder, N.N. Iossad, G. Rastelli, S. Ciuchi, and A. F. Morpurgo Nature Materials 5, 982 (2006).