# Suppression of Decoherence of a Spin-Boson System by Time-Periodic Control

## TL;DR

This paper demonstrates that time-periodic control can significantly suppress decoherence in a spin-boson quantum system, with the effectiveness quantified by bounds depending on coupling strength and control period.

## Contribution

It introduces a method to approximate the system's evolution under periodic control, providing bounds on decoherence suppression using Kato stability and non-autonomous evolution theory.

## Key findings

- Decoherence can be suppressed with small coupling and control periods
- Deviation between coupled and uncoupled dynamics is estimated by O(gtT)
- Approach relies on Kato stability and non-autonomous evolution theory

## Abstract

We consider a finite-dimensional quantum system coupled to the bosonic radiation field and subject to a time-periodic control operator. Assuming the validity of a certain dynamic decoupling condition we approximate the system's time evolution with respect to the non-interacting dynamics. For sufficiently small coupling constants $g$ and control periods $T$ we show that a certain deviation of coupled and uncoupled propagator may be estimated by $\mathcal{O}(gt \, T)$. Our approach relies on the concept of Kato stability and general theory on non-autonomous linear evolution equations.