Strong-Disorder Renormalization Group for Periodically Driven Systems

TL;DR

This paper introduces a real-space renormalization group method tailored for analyzing phase transitions in strongly disordered, periodically driven quantum systems, exemplified on the quantum Ising model, revealing universal critical behavior.

Contribution

It develops an asymptotically exact strong-disorder RG approach for Floquet systems, addressing disorder and time-translation symmetry complexities.

Findings

Universal critical behavior near phase transitions

Robustness of phases to weak interactions

Analysis of multicritical points in driven quantum systems

Abstract

Quenched randomness can lead to robust non-equilibrium phases of matter in periodically driven (Floquet) systems. Analyzing transitions between such dynamical phases requires a method capable of treating the twin complexities of disorder and discrete time-translation symmetry. We introduce a real-space renormalization group approach, asymptotically exact in the strong-disorder limit, and exemplify its use on the periodically driven interacting quantum Ising model. We analyze the universal physics near the critical lines and multicritical point of this model, and demonstrate the robustness of our results to the inclusion of weak interactions.