Starts 19 Mar 2024 11:00
Ends 19 Mar 2024 12:00
Central European Time
CMSP Seminar (Joint ICTP/SISSA Statistical Physics): Thermodynamics in non-equilibrium quantum systems: A Keldysh approach
room 128 (SISSA, via Bonomea), and via Zoom
Vasco Cavina
(Scuola Normale Superiore, Pisa)
Abstract:
The Keldysh contour is the backbone of both path integral and diagrammatic approaches to dissipative quantum systems, and has an extensive use in a variety of fields including quantum transport, quantum Brownian motion and critical phenomena. We will briefly introduce the idea behind the Keldysh contour, and show its applications in the field of quantum thermodynamics. In this context, we will discuss how to generalize the Keldysh idea to obtain the full energy statistics in closed and open quantum systems. This idea can be used to build approximate theories that are guaranteed to be thermodynamically consistent, that is, their predictions are by construction in agreement with the first and second laws of thermodynamics. We mention how to use these results to study the thermodynamics in two frameworks that are naturally based on the Keldysh contour: many-body perturbation theory and path integrals for open quantum systems.
As an application of the path integral technique, we introduce a method to compute the full energy statistics in a non-equilibrium version of the Caldeira-Leggett model, in which a system is coupled to an infinite collection of Gaussian (squeezed and displaced) reservoirs. Lastly, we investigate potential future developments, from stochastic quantum master equations to quantum chaos.
The Keldysh contour is the backbone of both path integral and diagrammatic approaches to dissipative quantum systems, and has an extensive use in a variety of fields including quantum transport, quantum Brownian motion and critical phenomena. We will briefly introduce the idea behind the Keldysh contour, and show its applications in the field of quantum thermodynamics. In this context, we will discuss how to generalize the Keldysh idea to obtain the full energy statistics in closed and open quantum systems. This idea can be used to build approximate theories that are guaranteed to be thermodynamically consistent, that is, their predictions are by construction in agreement with the first and second laws of thermodynamics. We mention how to use these results to study the thermodynamics in two frameworks that are naturally based on the Keldysh contour: many-body perturbation theory and path integrals for open quantum systems.
As an application of the path integral technique, we introduce a method to compute the full energy statistics in a non-equilibrium version of the Caldeira-Leggett model, in which a system is coupled to an infinite collection of Gaussian (squeezed and displaced) reservoirs. Lastly, we investigate potential future developments, from stochastic quantum master equations to quantum chaos.