Quadratic Dynamical Decoupling with Non-Uniform Error Suppression

TL;DR

This paper numerically analyzes the performance of quadratic dynamical decoupling (QDD) sequences for single-qubit error suppression, revealing how sequence parameters and parity affect decoherence mitigation.

Contribution

It provides a detailed numerical study of QDD's error suppression capabilities, highlighting the importance of sequence parameters and parity for optimal performance.

Findings

Error suppression depends on N1 and N2 parities.

Near-optimal performance occurs when N1 equals N2.

QDD effectively isolates and suppresses specific error components.

Abstract

We analyze numerically the performance of the near-optimal quadratic dynamical decoupling (QDD) single-qubit decoherence errors suppression method [J. West et al., Phys. Rev. Lett. 104, 130501 (2010)]. The QDD sequence is formed by nesting two optimal Uhrig dynamical decoupling sequences for two orthogonal axes, comprising N1 and N2 pulses, respectively. Varying these numbers, we study the decoherence suppression properties of QDD directly by isolating the errors associated with each system basis operator present in the system-bath interaction Hamiltonian. Each individual error scales with the lowest order of the Dyson series, therefore immediately yielding the order of decoherence suppression. We show that the error suppression properties of QDD are dependent upon the parities of N1 and N2, and near-optimal performance is achieved for general single-qubit interactions when N1=N2.