Resumé / Abstract :

The reaction-coordinate mapping is a way of redefining the boundary between system and reservoir that allows to treat limits inaccessible with standard approaches. It is implemented by identifying collective reservoir degrees of freedom and including them — at the level of the Hamiltonian — into a redefined system.

In particular regimes, this enlarged system can then be treated with standard methods. Within the context of electronic quantum transport, it is straightforward to apply a fermionic version of the mapping individually to every reservoir. This allows to revisit nonequilibrium phenomena from the perspective of strong-system reservoir couplings and non-Markovian effects.

In particular, I will demonstrate the benefits of the method by showing that performance of a continuously operating quantum heat engine may increase in the strong-coupling regime. Furthermore, for explicit feedback loops, the method can also be used to identify the thermodynamic cost of measurement and control operations, which for example allows for a revisiting of electronic Maxwell demons. Even models that are anyways exactly solvable may profit from conceptual insight gained from such transformations, which e.g. allows to identify non-Markovian limits by broken thermodynamic uncertainty relations.

Papers :

+ A. Nazir and G. Schaller, in F. Binder \em et al. (eds.), Thermodynamics in the quantum regime - Recent Progress and Outlook (Springer International Publishing), (2019).

+ G. Schaller \em et al., PRB 97, 195104 (2018).

+ P. Strasberg \em et al., \em ibid., 205405 (2018).

+ N. Martensen and G. Schaller, EPJB 92, 30 (2019).

Contact : equipe-seminaires-nano@fondation-nanosciences.fr