Hi all,
Tomorrow at 2pm Severin Meng will tell us about his master thesis, entitled "Thermodynamic Properties of Passive States". See below for the abstract. The meeting link is https://ethz.zoom.us/j/362994444.
Best,
Joe
Abstract:
A passive state is defined such that no unitary transformation can lower its average energy. Within the set of passive states one finds the well-known thermal states, which are described by a quantum analogue of classical temperature. Interesting quantities like the efficiency, cooling performance or even possibility of a state transition within settings that use a thermal state resource are characterised by the state's temperature and Hamiltonian. Non-thermal passive states appear naturally, for example at the end of a thermodynamic process like cooling, and they may thus be used as an initial state in a different thermodynamic scenario. There is no unique temperature of a non-thermal passive state that characterises its thermodynamic performance. We investigate which properties of passive states determine their thermodynamic behaviour. We approach this task by exploring different thermodynamic settings that involve passive states. The considered settings include an autonomous heat engine and refrigerator as well as state transformations and more abstract work extraction protocols. We find different parameters for the various scenarios that describe the thermodynamics of the passive state. The set of relevant parameters includes the temperatures of the thermal state of the same energy as well as the thermal state of the same entropy, the asymptotic activation energy, the free energy and entropy as well as specific combinations of energy gaps and virtual temperatures within the passive state.