5,312 research outputs found
Vector and Spinor Decomposition of SU(2) Gauge Potential, their quivalence and Knot Structure in SU(2) Chern-Simons Theory
In this paper, spinor and vector decomposition of SU(2) gauge potential are
presented and their equivalence is constructed using a simply proposal. We also
obtain the action of Faddeev nonlinear O(3) sigma model from the SU(2) massive
gauge field theory which is proposed according to the gauge invariant
principle. At last, the knot structure in SU(2) Chern-Simons filed theory is
discussed in terms of the --mapping topological current theory. The
topological charge of the knot is characterized by the Hopf indices and the
Brouwer degrees of -mapping.Comment: 10 pages, ni figur
Dynamical Response of Fermi Condensate to Varying Magnetic Fields
We investigate the dynamical response of strongly interacting ultra-cold
fermionic atoms near Feshbach resonance to varying magnetic fields. Following
the experimental practices, we calculate the response of the atoms to
oscillating and to linearly ramped magnetic fields respectively. For
oscillating magnetic fields, depending on the frequencies and the amplitudes of
the oscillations, the response of the pair excitation gap shows either linear
or rich non-linear behaviour. In addition, both the spectral studies through
the linear response theory and the time-domain simulations suggest the
existence of a resonant frequency corresponding to the pair dissociation
threshold. For linearly ramped magnetic fields, the response of the excitation
gap shows damped oscillations. The final value of the excitation gap depends on
the rate of the field sweep.Comment: 6 pages, 6 figure
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