2 research outputs found
Wootters' distance revisited: a new distinguishability criterium
The notion of distinguishability between quantum states has shown to be
fundamental in the frame of quantum information theory. In this paper we
present a new distinguishability criterium by using a information theoretic
quantity: the Jensen-Shannon divergence (JSD). This quantity has several
interesting properties, both from a conceptual and a formal point of view.
Previous to define this distinguishability criterium, we review some of the
most frequently used distances defined over quantum mechanics' Hilbert space.
In this point our main claim is that the JSD can be taken as a unifying
distance between quantum states.Comment: 15 pages, 3 figures, changed content, added reference for last
sectio
A Schroedinger link between non-equilibrium thermodynamics and Fisher information
It is known that equilibrium thermodynamics can be deduced from a constrained
Fisher information extemizing process. We show here that, more generally, both
non-equilibrium and equilibrium thermodynamics can be obtained from such a
Fisher treatment. Equilibrium thermodynamics corresponds to the ground state
solution, and non-equilibrium thermodynamics corresponds to excited state
solutions, of a Schroedinger wave equation (SWE). That equation appears as an
output of the constrained variational process that extremizes Fisher
information. Both equilibrium- and non-equilibrium situations can thereby be
tackled by one formalism that clearly exhibits the fact that thermodynamics and
quantum mechanics can both be expressed in terms of a formal SWE, out of a
common informational basis.Comment: 12 pages, no figure