36,492 research outputs found
Y(so(5)) symmtry of the nonlinear Schrdinger model with four-cmponents
The quantum nonlinear Schrdinger(NLS) model with four-component
fermions exhibits a symmetry when considered on an infintite
interval. The constructed generators of Yangian are proved to satisfy the
Drinfel'd formula and furthermore, the relation with the general form of
rational R-matrix given by Yang-Baxterization associated with algebraic
structure.Comment: 10 pages, no figure
Laser-induced charging of microfabricated ion traps
Electrical charging of metal surfaces due to photoelectric generation of
carriers is of concern in trapped ion quantum computation systems, due to the
high sensitivity of the ions' motional quantum states to deformation of the
trapping potential. The charging induced by typical laser frequencies involved
in doppler cooling and quantum control is studied here, with microfabricated
surface electrode traps made of aluminum, copper, and gold, operated at 6 K
with a single Sr ion trapped 100 m above the trap surface. The lasers
used are at 370, 405, 460, and 674 nm, and the typical photon flux at the trap
is 10 photons/cm/sec. Charging is detected by monitoring the ion's
micromotion signal, which is related to the number of charges created on the
trap. A wavelength and material dependence of the charging behavior is
observed: lasers at lower wavelengths cause more charging, and aluminum
exhibits more charging than copper or gold. We describe the charging dynamic
based on a rate equation approach.Comment: 8 pages, 8 figure
Shear viscosity, instability and the upper bound of the Gauss-Bonnet coupling constant
We compute the dimensionality dependence of for charged black branes
with Gauss-Bonnet correction. We find that both causality and stability
constrain the value of Gauss-Bonnet coupling constant to be bounded by 1/4 in
the infinite dimensionality limit. We further show that higher dimensionality
stabilize the gravitational perturbation. The stabilization of the perturbation
in higher dimensional space-time is a straightforward consequence of the
Gauss-Bonnet coupling constant bound.Comment: 16 pages,3 figures+3 tables,typos corrected, published versio
Algebraic Bethe Ansatz for Integrable Extended Hubbard Models Arising from Supersymmetric Group Solutions
Integrable extended Hubbard models arising from symmetric group solutions are
examined in the framework of the graded Quantum Inverse Scattering Method. The
Bethe ansatz equations for all these models are derived by using the algebraic
Bethe ansatz method.Comment: 15 pages, RevTex, No figures, to be published in J. Phys.
Semiclassical approach to the quantum Loschmidt echo in deep quantum regions: from validity to breakdown
Semiclassical results are usually expected to be valid in the semiclassical
regime. An interesting question is, in models in which appropriate effective
Planck constants can be introduced, to what extent will a semiclassical
prediction stay valid when the effective Planck constant is increased? In this
paper, we numerically study this problem, focusing on semiclassical predictions
for the decay of the quantum Loschmidt echo in deep quantum regions. Our
numerical simulations, carried out in the chaotic regime in the sawtooth model
and in the kicked rotator model and also in the critical region of a 1D Ising
chain in transverse field, show that the semiclassical predictions may work
even in deep quantum regions, in particularly, for perturbation strength in the
so-called Fermi-Golden-rule regime.Comment: 8 pages, 10 figures. Published versio
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