Kirkwood-Dirac quasiprobability distributions in quantum mechanics

Kirkwood-Dirac quasiprobability distributions in quantum mechanics

Seminar author:Gabriele De Chiara

Event date and time:06/19/2025 02:30:pm

Event location:Seminars Room, GIQ

Event contact:

In this tutorial, I will discuss the role of quasiprobability distributions (QPDs) in describing the statistics of measurement outcomes of observables measured at two or more times in quantum systems. QPDs have several applications in quantum thermodynamics, e.g., in defining the distribution of work done on or extracted from a quantum system, as well as in quantum many-body physics, given their connection to the Loschmidt echo and their use in analysing quantum quenches. I will focus on the Kirkwood-Dirac (KD) distribution, highlighting how the presence of initial coherence and the incompatibility of the measured observables can give rise to complex-valued quasiprobabilities. I will present simple illustrative examples and describe interferometric schemes that can be implemented experimentally to reconstruct the QPD.

Reference: 

Stefano Gherardini and Gabriele De Chiara, PRX Quantum 5, 030201 (2024).