4,738 research outputs found
Phase-Dependent Spontaneous Spin Polarization and Bifurcation Delay in Coupled Two-Component Bose-Einstein Condensates
The spontaneous spin polarization and bifurcation delay in two-component
Bose-Einstein condensates coupled with laser or/and radio-frequency pulses are
investigated. We find that the bifurcation and the spontaneous spin
polarization are determined by both physical parameters and relative phase
between two condensates. Through bifurcations, the system enters into the
spontaneous spin polarization regime from the Rabi regime. We also find that
bifurcation delay appears when the parameter is swept through a static
bifurcation point. This bifurcation delay is responsible for metastability
leading to hysteresis.Comment: Improved version for cond-mat/021157
Prospects for detection of via
At least one state in the first family of D-wave quarkonium levels
has been discovered near the predicted mass of 10.16 GeV/. This state is
probably the one with J=2. This state and the ones with J=1 and J=3 may
contribute a detectable amount to the decay , depending on the partial widths for these decays for which predictions
vary considerably. The prospects for detection of the chain are discussed.Comment: 4 pages, LaTeX, 1 figure, to be published in Phys. Rev. D, comment
added after Eq. (2
QCD Multipole Expansion and Hadronic Transitions in Heavy Quarkonium Systems
We review the developments of QCD multipole expansion and its applications to
hadronic transitions and some radiative decays of heavy quarkonia. Theoretical
predictions are compsred with updated experimental results.Comment: 23 pages, 7 figures. Some typos corrected, and 3 references adde
Finite dimensional quantizations of the (q,p) plane : new space and momentum inequalities
We present a N-dimensional quantization a la Berezin-Klauder or frame
quantization of the complex plane based on overcomplete families of states
(coherent states) generated by the N first harmonic oscillator eigenstates. The
spectra of position and momentum operators are finite and eigenvalues are
equal, up to a factor, to the zeros of Hermite polynomials. From numerical and
theoretical studies of the large behavior of the product of non null smallest positive and largest eigenvalues, we infer
the inequality (resp. ) involving, in suitable
units, the minimal () and maximal () sizes of
regions of space (resp. momentum) which are accessible to exploration within
this finite-dimensional quantum framework. Interesting issues on the
measurement process and connections with the finite Chern-Simons matrix model
for the Quantum Hall effect are discussed
Coulomb drag between quantum wires with different electron densities
We study the way back-scattering electron--electron interaction generates
Coulomb drag between quantum wires with different densities. At low temperature
the system can undergo a commensurate-- incommensurate transition as the
potential difference between the two wires passes a critical value
, and this transition is reflected in a marked change in the dependence
of drag resistivity on and . At high temperature a density difference
between the wires suppresses Coulomb drag induced by back scattering, and we
use the Tomonaga--Luttinger model to study this suppression in detail.Comment: 6 pages, 4 figure
Collapses and revivals of exciton emission in a semiconductor microcavity: detuning and phase-space filling effects
We investigate exciton emission of quantum well embedded in a semiconductor
microcavity. The analytical expressions of the light intensity for the cases of
excitonic number state and coherent state are presented by using secular
approximation. Our results show that the effective exciton-exciton interaction
leads to the appearance of collapse and revival of the light intensity. The
revival time is twice compared the coherent state case with that of the number
state. The dissipation of the exciton-polariton lowers the revival amplitude
but does not alter the revival time. The influences of the detuning and the
phase-space filling are studied. We find that the effect of the higher-order
exciton-photon interaction may be removed by adjusting the detuning.Comment: 7 pages, 3 figure
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