13th International Conference on the Exact Renormalization Group 2026 (ERG2026)

Many-body correlations in Floquet steady-states: Frequency-resolved renormalization group of the driven Anderson impurity

1 Sept 2026, 15:33

1m

Large Lecture Theatre (Jubilee Building)

Poster Poster presentations

Speakers

Dominik Chudy (RWTH Aachen University) Jan Herre (RWTH Aachen University)

Description

We introduce a functional renormalization group framework formulated directly in the Floquet steady-state that systematically incorporates frequency-dependent interaction effects. By retaining the frequency structure of the two-particle vertex up to second order in interaction strength, our approach provides controlled access to dynamical response functions and nonequilibrium transport in driven, interacting systems. Using the periodically driven single-impurity Anderson model as a paradigmatic example, we benchmark our results against state-of-the-art Floquet Green’s function methods and find quantitative agreement for finite-frequency observables up to intermediate interaction strengths. Remarkably, we also show that static properties are often captured reliably by much simpler approximations, suggesting practical pathways for modeling driven quantum materials. We demonstrate that, although periodic driving of the dot strongly broadens the Kondo resonance through inelastic scattering, it leaves the many-body Kondo cloud largely intact. This robustness suppresses Floquet replicas of the Kondo peak and leads to a partial persistence of Kondo pinning, highlighting the resilience of emergent many-body correlations under local periodic driving.
Finally, to extend our framework beyond impurity models we present first proof of concept results by implementing FRG using quantics tensor trains (QTT), taking advantage of scale separation in the frequency and momentum degree of freedom to reduce memory requirements. Utilizing tensor cross interpolation (TCI) one can construct the compressed representation directly from adaptive function evaluations, bypassing instantiation of the full tensor. Internal integrations can now be performed efficiently as tensor contractions, while convolution integrals can be executed via the discrete quantum Fourier transform represented as low-rank matrix product operators.