Optimal dynamical decoupling in the presence of colored control noise

TL;DR

This paper introduces a formalism for optimizing dynamical decoupling sequences in quantum systems by accounting for colored control noise, demonstrated with ultra-cold atom experiments.

Contribution

A new formalism that models the evolution of quantum systems with spectral functions of environment and control noise, enabling optimized decoupling sequences.

Findings

Spectral functions of environment and control noise can be measured and used for optimization.

The formalism improves quantum coherence preservation in realistic noisy conditions.

Experimental validation with ultra-cold Rubidium atoms confirms the approach's effectiveness.

Abstract

An optimal dynamical decoupling of a quantum system coupled to a noisy environment must take into account also the imperfections of the control pulses. We present a new formalism which describes, in a closed-form expression, the evolution of the system, including the spectral function of both the environment and control noise. We show that by measuring these spectral functions, our expression can be used to optimize the decoupling pulse sequence. We demonstrate this approach with an ensemble of optically trapped ultra-cold Rubidium atoms, and use quantum process tomography to identify the effect of the environment and control noise. Our approach is applicable and important for any realistic implementation of quantum information processing.