Holographic Floquet states in low dimensions (II)

TL;DR

This paper explores holographic Floquet states in a (2+1)-dimensional gauge theory under rotating electric fields, revealing phase diagram features, Floquet suppression points, and temperature effects on conductivity and photovoltaic currents.

Contribution

It extends previous work by analyzing temperature effects, phase diagrams, and new Floquet suppression states in holographic models of strongly coupled gauge theories.

Findings

Conductive phase persists at zero electric field at discrete frequencies.

Discovery of Floquet suppression points where vacuum polarization vanishes.

Temperature suppresses photovoltaic Hall current.

Abstract

We continue the study in [1] of a strongly coupled (2+1)-dimensional gauge theory subject to an external rotating electric field. The system is modelled holographically as a D3/D5 probe intersection. We add temperature to the D3 background and analyze the phase diagram. Also here, the conductive phase extends down to vanishing external electric field at discrete values of the frequencies where vector meson Floquet condensates form. For all temperatures, at given intercalated frequencies, we find new dual states that we name Floquet suppression points, where the vacuum polarization vanishes even in the presence of an electric field. From the data we infer that these states exist both in the conductive and insulating phases. In the massless limit we find a linear and instantaneous conductivity law, recovering known general results in 2+1 dimensions. We also examine the photovoltaic AC and DC current as the response to an oscillating probe electric field and see that rising the temperature suppresses the photovoltaic Hall current. All the results obtained carry over qualitatively unaltered to the case of D3/D7.