3,329 research outputs found
Quantum transitions and quantum entanglement from Dirac-like dynamics simulated by trapped ions
Quantum transition probabilities and quantum entanglement for two-qubit
states of a four level trapped ion quantum system are computed for
time-evolving ionic states driven by Jaynes-Cummings Hamiltonians with
interactions mapped onto a \mbox{SU}(2)\otimes \mbox{SU}(2) group structure.
Using the correspondence of the method of simulating a dimensional
Dirac-like Hamiltonian for bi-spinor particles into a single trapped ion, one
preliminarily obtains the analytical tools for describing ionic state
transition probabilities as a typical quantum oscillation feature. For
Dirac-like structures driven by generalized Poincar\'e classes of coupling
potentials, one also identifies the \mbox{SU}(2)\otimes \mbox{SU}(2) internal
degrees of freedom corresponding to intrinsic parity and spin polarization as
an adaptive platform for computing the quantum entanglement between the
internal quantum subsystems which define two-qubit ionic states. The obtained
quantum correlational content is then translated into the quantum entanglement
of two-qubit ionic states with quantum numbers related to the total angular
momentum and to its projection onto the direction of the trapping magnetic
field. Experimentally, the controllable parameters simulated by ion traps can
be mapped into a Dirac-like system in the presence of an electrostatic field
which, in this case, is associated to ionic carrier interactions. Besides
exhibiting a complete analytical profile for ionic quantum transitions and
quantum entanglement, our results indicate that carrier interactions actively
drive an overall suppression of the quantum entanglement.Comment: 27 pags, 5 fig
Magnon heralding in cavity optomagnonics
In the emerging field of cavity optomagnonics, photons are coupled coherently
to magnons in solid-state systems. These new systems are promising for
implementing hybrid quantum technologies. Being able to prepare Fock states in
such platforms is an essential step towards the implementation of quantum
information schemes. We propose a magnon-heralding protocol to generate a
magnon Fock state by detecting an optical cavity photon. Due to the
peculiarities of the optomagnonic coupling, the protocol involves two distinct
cavity photon modes. Solving the quantum Langevin equations of the coupled
system, we show that the temporal scale of the heralding is governed by the
magnon-photon cooperativity and derive the requirements for generating high
fidelity magnon Fock states. We show that the nonclassical character of the
heralded state, which is imprinted in the autocorrelation of an optical "read"
mode, is only limited by the magnon lifetime for small enough temperatures. We
address the detrimental effects of nonvacuum initial states, showing that high
fidelity Fock states can be achieved by actively cooling the system prior to
the protocol.Comment: 17 pages, 14 figures. Correction of typos, version as publishe
Maximal correlation between flavor entanglement and oscillation damping due to localization effects
Localization effects and quantum decoherence driven by the mass-eigenstate
wave packet propagation are shown to support a statistical correlation between
quantum entanglement and damped oscillations in the scenario of three-flavor
quantum mixing for neutrinos. Once the mass-eigenstates that support flavor
oscillations are identified as three-{\em qubit} modes, a decoherence scale can
be extracted from correlation quantifiers, namely the entanglement of formation
and the logarithmic negativity. Such a decoherence scale is compared with the
coherence length of damped oscillations. Damping signatures exhibited by flavor
transition probabilities as an effective averaging of the oscillating terms are
then explained as owing to loss of entanglement between mass modes involved in
the relativistic propagation.Comment: 13 pages, 03 figure
Micotoxinas em amêndoas da castanheira-do-brasil.
Durante a palestra serão discutidos os problemas inerentes à presença de aflatoxinas na cadeia produtiva de castanha-do-brasil, os resultados obtidos durante o desenvolvimento do projeto e seu potencial impacto para a melhoria da qualidade deste produto
Micotoxinas em amêndoas da castanheira-do-brasil.
Durante a palestra serão discutidos os problemas inerentes à presença de aflatoxinas na cadeia produtiva de castanha-do-brasil, os resultados obtidos durante o desenvolvimento do projeto e seu potencial impacto para a melhoria da qualidade deste produto
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