A holographic superfluid symphony

Abstract

We study the hydrodynamic excitations of backreacted holographic superfluids by computing the full set of quasinormal modes (QNMs) at finite momentum and matching them to the existing hydrodynamic theory of superfluids. Additionally, we analyze the behavior of the low-energy excitations in real frequency and complex momentum, going beyond the standard QNM picture. Finally, we carry out a novel type of study of the model by computing the support of the hydrodynamic modes across the phase diagram. We achieve this by determining the support of the corresponding QNMs on the different operators in the dual theory, both in complex frequency and complex momentum space. From the support, we are able to reconstruct the hydrodynamic dispersion relations using the hydrodynamic constitutive relations. Our analysis rules out a role-reversal phenomenon between first and second sound in this model, contrary to results obtained in a weakly coupled field theory framework.

Homes' law in holographic superconductor with linear-$T$ resistivity

“…15 We also checked that our numerical code produces the consistent result in [57]: the optical conductivity of the Gubser-Rocha model at k/µ = 0. 16 We checked that σ(ω = 0) is consistent with the analytic result in (2.13). For instance, see Fig.…”

“…Thereafter, there has been extensive development and extension of the HHH model in [5,6,11,12]. For the recent development of holographic superconductors, see also [13][14][15][16][17][18] and references therein.…”

Pseudo-spontaneous $U(1)$ Symmetry Breaking in Hydrodynamics and Holography

“…The complete superfluid hydrodynamics framework of [57] was successfully matched to holographic models in [58]. 2 We here assume that the superfluid chemical potential is identical to the normal fluid chemical potential.…”

“…The source λ, which we take to be real, of the dual operator is given by the leading term of the boundary expansion of ψ -we thus identify λ = ψ (l) 1 as well as ψ (l) 2 = 0. Next, in order to compute the expectation value we follow the procedure detailed in appendix A of [58], arriving at O = 2ψ…”

Homes’ law in holographic superconductor with linear-T resistivity

“…Thereafter, there has been extensive development and extension of the HHH model in [5,6,11,12]. For the recent development of holographic superconductors, see also [13][14][15][16][17][18] and references therein.…”