Preserving qubit coherence by dynamical decoupling

TL;DR

This paper reviews recent theoretical and experimental advances in dynamical decoupling techniques for protecting qubit coherence in noisy quantum environments, highlighting new pulse sequences like Uhrig DD.

Contribution

It provides a comprehensive overview of dynamical decoupling methods, including new developments such as Uhrig DD, and offers both semiclassical and quantum perspectives.

Findings

Uhrig DD employs fewer pulses for effective decoherence suppression.

Periodic and concatenated DD sequences are effective in various settings.

Theoretical models align with experimental demonstrations.

Abstract

In quantum information processing, it is vital to protect the coherence of qubits in noisy environments. Dynamical decoupling (DD), which applies a sequence of flips on qubits and averages the qubit-environment coupling to zero, is a promising strategy compatible with other desired functionalities such as quantum gates. Here we review the recent progresses in theories of dynamical decoupling and experimental demonstrations. We give both semiclassical and quantum descriptions of the qubit decoherence due to coupling to noisy environments. Based on the quantum picture, a geometrical interpretation of DD is presented. The periodic Carr-Purcell-Meiboom-Gill DD and the concatenated DD are reviewed, followed by a detailed exploration of the recently developed Uhrig DD, which employs the least number of pulses in an unequally spaced sequence to suppress the qubit-environment coupling to a given order of the evolution time. Some new developments and perspectives are also discussed.