Peak-Dip-Hump from Holographic Superconductivity

TL;DR

This paper investigates the fermionic spectral function in a holographic superconductor model, revealing a peak-dip-hump spectral shape similar to high-T_c superconductors and establishing a link between the fermionic gap and condensate formation.

Contribution

It demonstrates the emergence of a peak-dip-hump spectral feature in a holographic superconductor and connects the fermionic gap to the condensate, providing insights into fermion pairing mechanisms.

Findings

Spectral function exhibits peak-dip-hump lineshape.

Linear relation between fermionic gap and condensate.

Zero-temperature black hole has zero entropy after condensate back reaction.

Abstract

We study the fermionic spectral function in a holographic superconductor model. At zero temperature, the black hole has zero horizon and hence the entropy of the system is zero after the back reaction of the condensate is taken into account. We find the system exhibits the famous peak-dip-hump lineshape with a sharp low-energy peak followed by a dip then a hump at higher energies. This feature is widely observed in the spectrum of several high-T_c superconductors. We also find a linear relation between the gap in the fermionic spectrum and the condensate, indicating the condensate is formed by fermion pairing.