Resumenes de las Charlas Invitadas
The two Loschmidt daemons and the cause of infidelity
Horacio M. Pastawski
Facultad de Matemática, Astronomía y Física,
Universidad Nacional de Córdoba,
Ciudad Universitaria, 5000 Córdoba, Argentina.
communication prepared with the collaboration of P. Danieli, L.F.F. Foa Torres,
F.M. Cucchietti and P.R. Levstein.
Abstract
Any attempt to revert the arrow of time would require the action of a qualified being or
mechanisms called a Loschmidt daemon. We describe the experimental realizations of two of such
creatures. One of them, the hasty daemon, is characterized for an instantaneous action of
global effect: the change in the sign of the Hamiltonian. We discuss how the chaotic nature of a
Hamiltonian dynamics leads to large scale quantum entangled state very fragile towards
perturbations that degrades the fidelity of the evolution and prevents time reversal. There is an
alternative stubborn daemon, who acts extramurally, but its persistent action reinjecting
wave function amplitude is able to produce a full quantum state propagating backwards. We describe
the mechanisms that would control his action.
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