Dynamical decoupling for a qubit in telegraph-like noises

TL;DR

This paper provides an exact analysis of qubit decoherence under telegraph-like noise and dynamical decoupling, showing the limits of suppression and identifying optimal pulse sequences for short-time coherence preservation.

Contribution

It offers an exact decoherence function for a qubit in telegraph noise and demonstrates the optimality of certain dynamical decoupling sequences in short-time regimes.

Findings

Decoherence can be suppressed up to third order in time.

Periodic CPMG sequences are most effective for short-time coherence.

Decoherence suppression limit is established for telegraph-like noises.

Abstract

Based on the stochastic theory developed by Kubo and Anderson, we present an exact result of the decoherence function of a qubit in telegraph-like noises under dynamical decoupling control. We prove that for telegraph-like noises, the decoherence can be suppressed at most to the third order of the time and the periodic Carr-Purcell-Merboom-Gill sequences are the most efficient scheme in protecting the qubit coherence in the short-time limit.