---
title: "What are phase coherence and noise in quantum sequences, and how do they impact qubit fidelity?"
date: "2024-03-22T14:51:52+00:00"
url: "https://www.quantum-machines.co/faq/what-are-phase-coherence-and-noise-in-quantum-sequences-and-how-do-they-impact-qubit-fidelity/"
description: "Learn how DDS minimizes phase noise and maintains coherence, enhancing qubit fidelity and reliability in quantum computing systems."
---

# What are phase coherence and noise in quantum sequences, and how do they impact qubit fidelity?

Phase coherence refers to the stability of the phase relationship between signals over time, which is crucial for accurate qubit manipulation and information transfer. Phase noise, on the other hand, is a random, unpredictable, and irregular fluctuation seen on any given signal individually. This noise can disrupt not only the coherence between channels but also the operation each pulse is supposed to implement on the qubits. [Digital Direct Synthesis (DDS)](https://www.quantum-machines.co/technology/direct-digital-synthesis/) plays a vital role in minimizing noise and maintaining phase coherence, thereby enhancing qubit fidelity and the reliability of quantum computing systems.