Recovery maps in quantum thermodynamics

A research line that has been very active recently in quantum information is that of recoverability theorems. These, roughly speaking, quantify how well can quantum information be restored after some general CPTP map, through particular 'recovery maps'. In this talk, I will outline what this line of work can teach us about quantum thermodynamics.

On one hand, dynamical semigroups describing thermalization, namely Davies maps, have the curious property of being their own recovery map, as a consequence of a condition named quantum detailed balance. For these maps, we derive a tight bound relating the entropy production at time t with the state of the system at time 2t, which puts a strong constraint on how systems reach thermal equilibrium. 
On the other hand, we also show how the Petz recovery map appears in the derivation of quantum fluctuation theorems, as the reversed work-extraction process. From this fact alone, we show how a number of useful expressions follow. These include a generalization of the majorization conditions that includes fluctuating work, Crooks and Jarzynski's theorems, and an integral fluctuation theorem that can be thought of as the second law as an equality.

Event Type: 
Seminar
Scientific Area(s): 
Event Date: 
Wednesday, January 11, 2017 - 16:00 to 17:30
Location: 
Time Room