QM Talks@CBPF: Roberto M. Serra – 18.05, 16h00

This week we have many guests visiting the qig@CBPF: Roberto Serra (UFABC), Thiago Batalhão (UFABC), and Cristhiano Duarte (UFMG). Serra and Thiago are here to fine tune some details about an experiment our NMR crew is performing; while Cristhiano is here to work in a project on quantum channels from coarse-grained dynamics in collaboration with Fernando de Melo (that’s me).

We take this chance and asked Serra to deliver a talk on his latest results (which by the way involve some collaboration with the qig@CBPF). See the details below. See you there.

Title: Irreversibility and Maxwell’s Demons in quantum systems

Speaker: Roberto M. Serra – UFABC

Coordinates: Auditorium 6th floor, CBPF. 18.05, 16h00

Abstract: Maxwell’s demon explores the role of information in physical processes. Employing information about microscopic degrees of freedom, this “intelligent observer” is capable of compensating entropy production (or extracting work), apparently challenging the second law of thermodynamics. In a modern standpoint, it is regarded as a feedback control mechanism and the limits of thermodynamics are recast incorporating information-to-energy conversion into fluctuation theorems. Endeavors to incorporate information into thermodynamics acquire a pragmatic applicability within the recent technological progress, where information just started to be manipulated at the micro and nano-scale. In this seminar, we will discuss the panorama of the Thermodynamics of Information at Quantum Scales. We will introduce a trade-off relation between information-theoretic quantities empowering the design of an efficient Maxwell’s demon in a quantum system. Moreover, an experimental implementation of the Demon will also be presented. Such a creature is materialised as a spin-1/2 quantum memory that acquires information, and employs it to control the dynamics of another spin-1/2 system, through a natural interaction in a NMR setup. This realisation provides experimental evidence that assessing microscopic information and applying a feed-forward strategy at the quantum scale can mitigate the irreversibility on a non-equilibrium dynamics.