Thermodynamics of Quantum Collisions

In this thesis, we show how the thermodynamic concepts of heat and work arise at the level of a quantum collision. We consider the collision of a particle travelling in space, described by a wave packet, with a fixed system having internal energy states. Our main finding is that the energy width of the wave packet, which can be narrow or broad with respect to the system energies, plays a crucial role in identifying energy exchanges due to collisions as heat or work. While heat is generated by narrow wave packets effusing with thermal momenta, work is generated by fast and broad wave packets. We compare our results with models of repeated interactions, which despite being inspired by quantum collisions, still present shortcomings when used as a basis for a thermodynamic theory. We show how these difficulties are circumvented by a proper application of quantum scattering theory.