Accurate effective Hamiltonians via unitary flow in Floquet space

TL;DR

This paper introduces a systematic method to derive effective, time-independent Hamiltonians for periodically driven quantum systems using flow equations in Floquet space, explaining experimental tunneling deviations.

Contribution

It develops a novel approach employing flow equations in Floquet space to construct effective Hamiltonians for driven quantum systems, bridging theory and experimental observations.

Findings

Successfully derives effective Hamiltonians for driven systems.

Explains deviations in tunneling suppression observed experimentally.

Provides a framework for analyzing periodically driven quantum systems.

Abstract

We present a systematic construction of effective Hamiltonians of periodically driven quantum systems. Because of an equivalence between the time dependence of a Hamiltonian and an interaction in its Floquet operator, flow equations, that permit to decouple interacting quantum systems, allow us to identify time-independent Hamiltonians for driven systems. With this approach, we explain the experimentally observed deviation of expected suppression of tunneling in ultracold atoms.