607 research outputs found
Searching for pairing energies in phase space
We obtain a representation of pairing energies in phase space, for the
Lipkin-Meshkov-Glick and general boson Bardeen-Cooper-Schrieffer pairing
models. This is done by means of a probability distribution of the quantum
state in phase space. In fact, we prove a correspondence between the points at
which this probability distribution vanishes and the pairing energies. In
principle, the vanishing of this probability distribution is experimentally
accessible and additionally gives a method to visualize pairing energies across
the model control parameter space. This result opens new ways to experimentally
approach quantum pairing systems.Comment: 5 pages, 4 figure
Wave packet revivals in a graphene quantum dot in a perpendicular magnetic field
We study the time-evolution of localized wavepackets in graphene quantum dots
under a perpendicular magnetic field, focusing on the quasiclassical and
revival periodicities, for different values of the magnetic field intensities
in a theoretical framework. We have considered contributions of the two
inequivalent points in the Brillouin zone. The revival time has been found as
an observable that shows the break valley degeneracy.Comment: 5 pages, 4 figures, corrected typo, To appear in Phys. Rev.
A Generalized Statistical Complexity Measure: Applications to Quantum Systems
A two-parameter family of complexity measures
based on the R\'enyi entropies is introduced and characterized by a detailed
study of its mathematical properties. This family is the generalization of a
continuous version of the LMC complexity, which is recovered for and
. These complexity measures are obtained by multiplying two quantities
bringing global information on the probability distribution defining the
system. When one of the parameters, or , goes to infinity, one
of the global factors becomes a local factor. For this special case, the
complexity is calculated on different quantum systems: H-atom, harmonic
oscillator and square well.Comment: 15 pages, 3 figure
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