39,304 research outputs found

    Removable singularities of the CscK metric

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    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

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    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 Δ\Delta-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

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    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

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    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

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    In this paper, we investigate the p+iip superfluid phases in the complex vector field holographic p-wave model. We find that in the probe limit, the p+iip phase and the p-wave phase are equally stable, hence the p and iip orders can be mixed with an arbitrary ratio to form more general p+λi\lambda ip phases, which are also equally stable with the p-wave and p+iip 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+iip 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+iip phases to the normal phase, there is a temperature region where the p+iip phase exists but the p-wave phase doesn't. In this region we find the stable p+iip phase for the first time.Comment: 16 pages, 5 figures; typos correcte

    Thermalization of Topological Entropy after a Quantum Quench

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    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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