6,738 research outputs found
The effect of hidden color channels on nucleon-nucleon interaction in quark model
In the framework of constituent quark model, the effect of hidden color
channels on the nucleon-nucleon () interaction is studied. By adjusting the
color confinement strength between the hidden color channels and color singlet
channels and/or between the hidden color channels and hidden color channels,
the experimental data of to partial-wave phase shifts of
scattering can be fitted well. The results show that the hidden color channel
coupling might be important in producing the intermediate-range attraction of
interaction. The deuteron properties and dibaryon candidates have also
been studied with this model.Comment: 11 pages, 9 figure
Self-trapping of a Fermi super-fluid in a double-well potential in the BEC-unitarity crossover
We derive a generalized Gross-Pitaevskii density-functional equation
appropriate to study the Bose-Einstein condensate (BEC) of dimers formed of
singlet spin-half Fermi pairs in the BEC-unitarity crossover while the
dimer-dimer scattering length changes from 0 to . Using an
effective one-dimensional form of this equation, we study the phenomenon of
dynamical self-trapping of a cigar-shaped Fermi super-fluid in the entire
BEC-unitarity crossover in a double-well potential. A simple two-mode model is
constructed to provide analytical insights. We also discuss the consequence of
our study on the self-trapping of an atomic BEC in a double-well potential.Comment: 10 pages, 9 figure
Optical waveform sampling of a 320 Gbits/s serial data signal using a hydrogenated amorphous silicon waveguide
We propose using a hydrogenated amorphous silicon waveguide for ultra-high-speed serial data waveform sampling. 320 Gbit/s serial optical data sampling is experimentally demonstrated with +12 dB intrinsic four wave mixing conversion efficiency
On the single mode approximation in spinor-1 atomic condensate
We investigate the validity conditions of the single mode approximation (SMA)
in spinor-1 atomic condensate when effects due to residual magnetic fields are
negligible. For atomic interactions of the ferromagnetic type, the SMA is shown
to be exact, with a mode function different from what is commonly used.
However, the quantitative deviation is small under current experimental
conditions (for Rb atoms). For anti-ferromagnetic interactions, we find
that the SMA becomes invalid in general. The differences among the mean field
mode functions for the three spin components are shown to depend strongly on
the system magnetization. Our results can be important for studies of beyond
mean field quantum correlations, such as fragmentation, spin squeezing, and
multi-partite entanglement.Comment: Revised, newly found analytic proof adde
Fidelity susceptibility and long-range correlation in the Kitaev honeycomb model
We study exactly both the ground-state fidelity susceptibility and bond-bond
correlation function in the Kitaev honeycomb model. Our results show that the
fidelity susceptibility can be used to identify the topological phase
transition from a gapped A phase with Abelian anyon excitations to a gapless B
phase with non-Abelian anyon excitations. We also find that the bond-bond
correlation function decays exponentially in the gapped phase, but
algebraically in the gapless phase. For the former case, the correlation length
is found to be , which diverges
around the critical point .Comment: 7 pages, 6 figure
High-Order Adiabatic Approximation for Non-Hermitian Quantum System and Complexization of Berry's Phase
In this paper the evolution of a quantum system drived by a non-Hermitian
Hamiltonian depending on slowly-changing parameters is studied by building an
universal high-order adiabatic approximation(HOAA) method with Berry's phase
,which is valid for either the Hermitian or the non-Hermitian cases. This
method can be regarded as a non-trivial generalization of the HOAA method for
closed quantum system presented by this author before. In a general situation,
the probabilities of adiabatic decay and non-adiabatic transitions are
explicitly obtained for the evolution of the non-Hermitian quantum system. It
is also shown that the non-Hermitian analog of the Berry's phase factor for the
non-Hermitian case just enjoys the holonomy structure of the dual linear bundle
over the parameter manifold. The non-Hermitian evolution of the generalized
forced harmonic oscillator is discussed as an illustrative examples.Comment: ITP.SB-93-22,17 page
Modulational instability of spinor condensates
We demonstrate, analytically and numerically, that the ferromagnetic phase of
the spinor Bose-Einstein condenstate may experience modulational instability of
the ground state leading to a fragmentation of the spin domains. Together with
other nonlinear effects in the atomic optics of ultra-cold gases (such as
coherent photoassociation and four-wave mixing) this effect provides one more
analogy between coherent matter waves and light waves in nonlinear optics.Comment: 4 pages, 4 figures. Accepted for Phys. Rev. A Rapid Communication
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