44,363 research outputs found
Flatness-based control of a single qubit gate
This work considers the open-loop control problem of steering a two level
quantum system from an initial to a final condition. The model of this system
evolves on the state space SU(2), having two inputs that correspond to the
complex amplitude of a resonant laser field. A symmetry preserving flat output
is constructed using a fully geometric construction and quaternion
computations. Simulation results of this flatness-based open-loop control are
provided.Comment: Submitted to IEEE AC. Simulation code available at
http://cas.ensmp.fr/~rouchon/publications/PR2007/CodeMatlabScilabQubit.zi
A Time-Periodic Lyapunov Approach for Motion Planning of Controllable Driftless Systems on SU(n)
For a right-invariant and controllable driftless system on SU(n), we consider
a time-periodic reference trajectory along which the linearized control system
generates su(n): such trajectories always exist and constitute the basic
ingredient of Coron's Return Method. The open-loop controls that we propose,
which rely on a left-invariant tracking error dynamics and on a fidelity-like
Lyapunov function, are determined from a finite number of left-translations of
the tracking error and they assure global asymptotic convergence towards the
periodic reference trajectory. The role of these translations is to avoid being
trapped in the critical region of this Lyapunov-like function. The convergence
proof relies on a periodic version of LaSalle's invariance principle and the
control values are determined by numerical integration of the dynamics of the
system. Simulations illustrate the obtained controls for and the
generation of the C--NOT quantum gate.Comment: Submitte
Mosca branca (Bemisia argentifolii): nova praga no Meio-Norte do Brasil.
bitstream/item/83452/1/CT930001.pd
Utilização de material reciclado para confecção de bebedouro semi-automático para criação de galinhas caipiras na agricultura familiar.
bitstream/item/58017/1/CT201.pd
Spontaneous CP violation in the 3-3-1 model with right-handed neutrinos
We implement the mechanism of spontaneous CP violation in the 3-3-1 model
with right-handed neutrinos and recognize their sources of CP violation. Our
main result is that the mechanism works already in the minimal version of the
model and new sources of CP violation emerges as an effect of new physics at
energies higher than the electroweak scale.Comment: Major changes in the quark sector, electronic dipole moment of the
neutron was evaluated, accepted for publication in the physical review
Majorana Dark Matter in Minimal Higgs Portal Models after LUX
We consider the Singlet Majorana fermion dark matter model, in which the
standard model particles interact with the dark sector through the mixing of a
singlet scalar and the Higgs boson. In this model both the dark matter and the
singlet scalar carry lepton number, the latter being a bilepton. We suppose the
existence of a symmetry, remnant of some high energy local symmetry
breaking, that stabilizes the Majorana fermion. We analyzed the parameter space
of this model and found that the lepton number symmetry breaking scale, drove
by the singlet scalar, is constrained to be within hundreds to thousands of
GeV, so as to conform with the observed dark matter relic density. Finally, we
address the direct detection and invisible Higgs decay complementarity,
confronting our model with recent LUX and LHC constraints, as well as XENON1T
prospects.Comment: 20 pages, 12 figure
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