40,145 research outputs found
Removable singularities of the CscK metric
In this paper, we consider a CscK metric defined away from divisor and with
metric upper bound and lower bound going to zero in certain rate. And we'll
prove that this "nicely" behaved metric is a smooth CscK metric across the
divisor.Comment: presentation improve
P-T phase diagram of a holographic s+p model from Gauss-Bonnet gravity
In this paper, we study the holographic s+p model in 5-dimensional bulk
gravity with the Gauss-Bonnet term. We work in the probe limit and give the
-T phase diagrams at three different values of the Gauss-Bonnet
coefficient to show the effect of the Gauss-Bonnet term. We also construct the
P-T phase diagrams for the holographic system using two different definitions
of the pressure and compare the results.Comment: 17 pages, 5 figures, we have added new P-T phase diagrams with the
pressure defined in boundary stress-energy tenso
Induced interaction in a spin-polarized Fermi gas
We study the effect of the induced interaction on the superfluidtransition
temperature of a spin-polarized Fermi gas. In the BCS limit, the polarization
is very small in the superfluid state, and the effect of the induced
interaction is almost the same as in the spin-balanced case. The temperature Tt
and the polarization Pt of the tricritical point are both reduced from
mean-field results by a factor about 2.22. This reduction is also significant
beyond the BCS limit. In the unitary limit, we find (Pt,Tt/TF)=(0.42,0.16), in
comparison with mean-field and experimental results.Comment: 6 pages, 2 figure
Spin-Orbit Coupled Fermi Gases across a Feshbach Resonance
In this letter we study both ground state properties and the superfluid
transition temperature of a spin-1/2 Fermi gas across a Feshbach resonance with
a synthetic spin-orbit coupling, using mean-field theory and exact solution of
two-body problem. We show that a strong spin-orbit coupling can significantly
enhance the pairing gap for 1/(k_F a_s)<=0 due to increased density-of-state.
Strong spin-orbit coupling also significantly enhances the superfluid
transition temperature when 1/(k_F a_s)<=0, while suppresses it slightly when
1/(k_F a_s)>0. The universal interaction energy and pair size at resonance are
also discussed.Comment: 4+3 pages, 4 figures, supplementary material adde
Split degenerate states and stable p+ip phases from holography
In this paper, we investigate the p+p superfluid phases in the complex
vector field holographic p-wave model. We find that in the probe limit, the
p+p phase and the p-wave phase are equally stable, hence the p and p
orders can be mixed with an arbitrary ratio to form more general p+p
phases, which are also equally stable with the p-wave and p+p phases. As a
result, the system possesses a degenerate thermal state in the superfluid
region. We further study the case with considering the back reaction on the
metric, and find that the degenerate ground states will be separated into
p-wave and p+p phases, and the p-wave phase is more stable. Finally, due to
the different critical temperature of the zeroth order phase transitions from
p-wave and p+p phases to the normal phase, there is a temperature region
where the p+p phase exists but the p-wave phase doesn't. In this region we
find the stable p+p phase for the first time.Comment: 16 pages, 5 figures; typos correcte
Thermalization of Topological Entropy after a Quantum Quench
In two spatial dimensions, topological order is robust for static
deformations at zero temperature, while it is fragile at any finite
temperature. How robust is topological order after a quantum quench? In this
paper we show that topological order thermalizes under the unitary evolution
after a quantum quench. If the quench preserves gauge symmetry, there is a
residual topological entropy exactly like in the finite temperature case.
We obtain this result by studying the time evolution of the topological
2-R\'enyi entropy in a fully analytical, exact way. These techniques can be
then applied to systems with strong disorder to show whether a many-body
localization phenomenon appears in topologically ordered systems.Comment: new plot with finite time results added; typos fixe
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