# Environmental noise spectroscopy with qubits subjected to dynamical decoupling

## TL;DR

This paper reviews how qubits under dynamical decoupling can be used to spectrally analyze environmental noise, addressing Gaussian and non-Gaussian quantum noise, with connections to various solid-state qubit experiments.

## Contribution

It provides a comprehensive theoretical overview of DD-based noise spectroscopy, including non-Gaussian and quantum noise effects, linked to experimental implementations.

## Key findings

- Theoretical framework for noise spectral density reconstruction
- Analysis of non-Gaussian and quantum noise effects
- Relevance to solid-state qubits like quantum dots, superconducting, and NV centers

## Abstract

A qubit subjected to pure dephasing due to classical Gaussian noise can be turned into a spectrometer of this noise by utilizing its readout under properly chosen dynamical decoupling (DD) sequences to reconstruct the power spectral density of the noise. We review the theory behind this DD-based noise spectroscopy technique, paying special attention to issues that arise when the environmental noise is non-Gaussian and/or it has truly quantum properties. While we focus on the theoretical basis of the method, we connect the discussed concepts with specific experiments and provide an overview of environmental noise models relevant for solid-state based qubits, including quantum-dot based spin qubits, superconducting qubits, and NV centers in diamond.