CPT

Calendar of Physics Talks Vienna

What happens to entropy production when conserved quantities fail to commute
Speaker:Nicole Yunger Halpern (University of Maryland)
Abstract:We extend entropy production to a deeply quantum regime involving noncommuting conserved quantities. Consider a unitary transporting conserved quantities (“charges”) between two systemsinitialized in thermal states. Three common formulae model the entropy produced. They respec-tively cast entropy as an extensive thermodynamic variable, as an information-theoretic uncertainty measure, and as a quantifier of irreversibility. Often, the charges are assumed to commute with each other (e.g., energy and particle number). Yet quantum charges can fail to commute. Noncom- mutation invites generalizations, which we posit and justify, of the three formulae. Charges’ non- commutation, we find, breaks the formulae’s equivalence. Furthermore, different formulae quantify different physical effects of charges’ noncommutation on entropyproduction. For instance, entropy production can signal contextuality
Date: Tue, 11.07.2023
Time: 15:00
Duration: 45 min
Location:ZE 01-1
Contact:Marcus Huber