Order parameter fluctuations in the holographic superconductor

TL;DR

This paper explores order parameter fluctuations in holographic superconductors, computing spectral functions with backreaction, and introduces a large-N Ginzburg-Landau model to explain the absence of certain modes, revealing a relativistic multi-component superfluid behavior.

Contribution

It provides a detailed analysis of order parameter fluctuations using a fully backreacted geometry and introduces a large-N Ginzburg-Landau model to interpret spectral features.

Findings

Spectral functions computed for normal and superconducting phases.

Higgs and second-sound modes are absent in spectral functions.

Holographic superconductor models a relativistic multi-component superfluid.

Abstract

We investigate the effect of order parameter fluctuations in the holographic superconductor. In particular, using a fully backreacted bulk geometry, the intrinsic spectral functions of the order parameter in both the normal and the superconducting phase are computed. We also present a vector-like large-$N$ version of the Ginzburg-Landau model that accurately describes our long-wavelength results in both phases. The large-$N$ limit of the latter model explains why the Higgs mode and the second-sound mode are not present in the spectral functions. Our results indicate that the holographic superconductor describes a relativistic multi-component superfluid in the universal regime of the BEC-BCS crossover.