Universal dynamical decoupling of multiqubit states from environment

TL;DR

This paper demonstrates that the nested Uhrig dynamical decoupling (NUDD) sequence can universally protect multiqubit states from decoherence, regardless of the specific system-environment interactions, using an efficient pulse scheme.

Contribution

It proves the universality of NUDD for multiqubit systems and introduces a mapping between dynamical decoupling and discrete quantum walks.

Findings

NUDD sequence suppresses decoherence to order N with (N+1)^2m pulses.

NUDD is universal, effective for any system-environment interaction.

A novel mapping links dynamical decoupling to quantum walks.

Abstract

We study the dynamical decoupling of multiqubit states from environment. For a system of m qubits, the nested Uhrig dynamical decoupling (NUDD) sequence can efficiently suppress generic decoherence induced by system-environment interaction to order N using (N+1)^2m pulses. We prove that the NUDD sequence is universal, i.e., it can restore the coherence of m-qubit quantum system independent of the details of system-environment interaction. We also construct a general mapping between dynamical decoupling problems and discrete quantum walks in certain functional spaces.