Adiabatic Non-Equilibrium Steady States in the Partition Free Approach

Consider a small sample coupled to a finite number of leads and assume that the total (continuous) system is at thermal equilibrium in the remote past. We construct a non-equilibrium steady state (NESS) by adiabatically turning on an electrical bias between the leads. The main mathematical challenge is to show that certain adiabatic wave operators exist and to identify their strong limit when the adiabatic parameter tends to zero. Our NESS is different from, though closely related with the NESS provided by the Jakšić–Pillet–Ruelle approach. Thus we partly settle a question asked by Caroli et al. (J. Phys. C Solid State Phys. 4(8):916–929, 1971 ) regarding the (non)equivalence between the partitioned and partition-free approaches.