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Colóquio IF com Prof. Takashi Nakamura - Institute of Science (Tokyo)
24/09, às 16h. No Auditório Abrahão de Moraes com transmissão ao vivo.

As redes neurais que impulsionam a IA

Convite à Física com Prof. Nestor Caticha (DFGE)
Em 23/09, 4ª feira, às 18h. No Aud. Abrahão de Moraes
 

Confira em: https://www.youtube.com/@dfmaifusp/streams

Exact thermodynamic inference in classical and quantum systems

Seminário de Física Estatística com Gustavo A. L. Forão, Universidade de São Paulo
Em 23/09, 4ª feira, às 15h. Sala de Seminários (2061), Departamento de Física Geral.

Resumo: Classical and quantum thermodynamics share a problem: the quantities theory speaks of are rarely the ones an experiment can reach. Hidden transitions in a Markov network and coherences inside a working medium are inaccessible for different reasons, but both leave the same gap between prediction and measurement, and both are usually addressed by bounding what cannot be seen. We show that the gap closes exactly. A system relaxing after a perturbation of arbitrary strength obeys a single closed equation, fixed by the network itself and indifferent to how hard the system is driven. The argument never uses the classical nature of the dynamics, so it carries over unchanged to the quantum case, where coherences stand on the same footing as populations. Its consequence is that the full thermodynamics can be reconstructed exactly from a handful of measurements taken wherever the apparatus allows. We show that in a three-qubit absorption refrigerator, where the cooling power and the coherence that carries the cooling cycle follow from the reservoirs alone, while the qubit the machine exists to cool is never touched.