Holography of charged dilatonic black branes at finite temperature

TL;DR

This paper explores finite-temperature charged dilatonic black branes in AdS space, revealing complex holographic phenomena like phase transitions, conductivity behaviors, and universal zero-temperature limits, through numerical solutions with various charge and scalar configurations.

Contribution

It provides a comprehensive numerical analysis of charged dilatonic black branes with scalar hair, uncovering rich holographic phenomenology and universal conductivities at zero temperature.

Findings

Phase transitions linked to scalar operator VEVs.

Non-monotonic electric conductivity with frequency and temperature.

Universal power-law behavior of optical conductivity at zero temperature.

Abstract

We investigate bulk and holographic features of finite-temperature black brane solutions of 4D anti-de Sitter Einstein-Maxwell-dilaton-gravity (EMDG). We construct, numerically, black branes endowed with non trivial scalar hairs for broad classes of EMDG. We consider both exponential and power-law forms for the coupling functions, as well as several charge configurations: purely electric, purely magnetic and dyonic solutions. At finite temperature the field theory holographically dual to these black brane solutions has a rich and interesting phenomenology reminiscent of electron motion in metals: phase transitions triggered by nonvanishing VEV of scalar operators, non-monotonic behavior of the electric conductivities as function of the frequency and of the temperature, Hall effect and sharp synchrotron resonances of the conductivity in presence of a magnetic field. Conversely, in the zero temperature limit the conductivities for these models show a universal behavior. The optical conductivity has a power-law behavior as a function of the frequency, whereas the DC conductivity is suppressed at small temperatures.