Spin polarization through Floquet resonances in a driven central spin model

TL;DR

This paper demonstrates how controlled periodic driving in a central spin model can induce Floquet resonances that enable spin polarization and decoupling from the environment, using integrability to explicitly construct the Floquet Hamiltonian.

Contribution

It introduces a method to analyze Floquet resonances in an integrable many-body system, enabling explicit construction of the Floquet Hamiltonian and control of spin polarization.

Findings

Floquet resonances can be used to decouple the central spin from its environment.

Integrability allows explicit construction of the Floquet Hamiltonian in the central spin model.

Controlled driving induces polarization transitions at resonance.

Abstract

Adiabatically varying the driving frequency of a periodically-driven many-body quantum system can induce controlled transitions between resonant eigenstates of the time-averaged Hamiltonian, corresponding to adiabatic transitions in the Floquet spectrum and presenting a general tool in quantum many-body control. Using the central spin model as an application, we show how such controlled driving processes can lead to a polarization-based decoupling of the central spin from its decoherence-inducing environment at resonance. While it is generally impossible to obtain the exact Floquet Hamiltonian in driven interacting systems, we exploit the integrability of the central spin model to show how techniques from quantum quenches can be used to explicitly construct the Floquet Hamiltonian in a restricted many-body basis and model Floquet resonances.