Holographic Systems out of Equilibrium: From Flavor Branes to SYK Wormholes

TL;DR

This paper explores the non-equilibrium behavior of strongly coupled quantum systems using holographic duality, analyzing phase structures, symmetry breaking, and wormhole traversability under periodic driving in various models.

Contribution

It introduces new holographic models for non-equilibrium dynamics, including Floquet phases and driven SYK wormholes, revealing rich phase structures and dynamical access to unstable regions.

Findings

Identified non-equilibrium phases with Floquet condensates and suppression points.

Showed magnetic fields can restore chiral symmetry in holographic models.

Demonstrated control over wormhole traversability via periodic driving.

Abstract

This thesis studies the non-equilibrium dynamics of strongly coupled quantum systems within the framework of the AdS/CFT correspondence, with particular emphasis on periodically driven (Floquet) systems. The first part focuses on top-down holographic constructions based on D3/D5 and D3/D7 brane intersections subjected to time-dependent external fields. In the D3/D5 system at finite temperature, we analyze the response to a rotating electric field and uncover a rich non-equilibrium phase structure containing conductive and insulating phases, vector meson Floquet condensates, and Floquet suppression points. In the D3/D7 setup, we study the effects of helical magnetic fields on chiral symmetry breaking, showing that sufficiently helical magnetc fields can restore chiral symmetry. The second part examines the periodically driven Maldacena-Qi model, a two-site extension of the SYK model dual to a traversable wormhole. We identify resonances that enhance or suppress the wormhole traversability and find evidence that the unstable region of the phase diagram can be dynamically accessed. We use our driving protocols to access this region and compute its Lyapunov exponent. Overall, this thesis advances the use of the holographic techniques to probe non-equilibrium steady states and real-time dynamics in strongly coupled quantum systems.