222 research outputs found
Practically state-independent test of contextuality with 9 observables
We propose a test of quantum contextuality for a single three-level system
that uses nine projective measurements. It has a form of an inequality that has
to be satisfied by any non-contextual theory and which is violated by any
quantum state, except for the maximally mixed one. Due to the fact that there
is only a single state that does not exhibit contextuality, it is natural to
ask what the difference between state-independent tests and the one proposed
here is.Comment: 3 pages, 1 figur
Information processing in biological molecular machines
Biological molecular machines are bi-functional enzymes that simultaneously
catalyze two processes: one providing free energy and second accepting it.
Recent studies show that most protein enzymes have a rich dynamics of
stochastic transitions between the multitude of conformational substates that
make up their native state. It often manifests in fluctuating rates of the
catalyzed processes and the presence of short-term memory resulting from the
preference of selected conformations. For any stochastic protein machine
dynamics we proved a generalized fluctuation theorem that leads to the
extension of the second law of thermodynamics. Using them to interpret the
results of random walk on a complex model network, we showed the possibility of
reducing free energy dissipation at the expense of creating some information
stored in memory. The subject of our analysis is the time course of the
catalyzed processes expressed by sequences of jumps at random moments of time.
Since similar signals can be registered in the observation of real systems, all
theses of the paper are open to experimental verification. From a broader
physical point of view, the division of free energy into the operation and
organization energies is worth emphasizing. Information can be assigned a
physical meaning of a change in the value of both these functions of state.Comment: The manuscript contains 14 pages, 7 figure
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