Patrice CAMATI

The emergent field of Quantum Thermodynamics extends thermodynamic concepts to small quantum systems. A number of important results have been obtained in the past decades, e.g., quantum fluctuation relations and thermodynamic uncertainty relations, among others. Many of the results consider a system coupled to a heat reservoir and/or driven by a time-dependent Hamiltonian to define the widely accepted notions of work and heat. Apart from such settings, there is currently no consensus on how work and heat should be defined. How can heat be defined without resorting to the coupling with a heat reservoir? For strongly coupled quantum systems, how should we handle the non-negligible coupling energy? Can notions of work and heat be defined for two interacting qubits? A number of proposals have been made and this endeavor is still an open problem, comprising an active research area in the field. I will review the accepted notion of work and heat and discuss a few proposals put forth recently. In particular, I will present and discuss some consequences of a general energetic framework we have been developing. In this talk, we will discuss the conceptual hurdles of extending thermodynamic concepts to non-thermodynamic settings.