Peak-Dip-Hump from Holographic Superconductivity

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.

Figures (2)

• Figure 1: A typical fermionic spectral function with the peak-dip-hump structure for $k=0.7$ (black dotted) $0.9$ (red dashed) $1.5$ (blue line) $2.5$ (purple dotdashed). A sharp peak develops when $k$ increases and the peak disappears above the Fermi momentum $k_{F}$. Here, $\rho =10$ and $q=1.7$.
• Figure 2: 3D plot of the fermionic spectral function with the peak-dip-hump structure. Here, $\rho =10$ and $q=1.7$.