Optimized Noise Filtration through Dynamical Decoupling

TL;DR

This paper introduces optimized dynamical decoupling sequences for qubits that significantly improve phase error suppression in high-frequency noise environments, validated through theoretical analysis and experiments with $^{9}$Be$^{+}$ ions.

Contribution

It presents a new analytical method for designing noise-filtering sequences that are spectrum-independent, enhancing qubit coherence in high-frequency noise conditions.

Findings

Sequences outperform traditional methods in high-frequency noise suppression

Experimental validation with $^{9}$Be$^{+}$ ions demonstrates effectiveness

Sequences are spectrum-independent up to a single scaling factor

Abstract

One approach to maintaining phase coherence of qubits through dynamical decoupling consists of applying a sequence of Hahn spin-echo pulses. Recent studies have shown that, in certain noise environments, judicious choice of the delay times between these pulses can greatly improve the suppression of phase errors compared to traditional approaches. By enforcing a simple analytical condition, we obtain sets of dynamical decoupling sequences that are designed for optimized noise filtration and are spectrum-independent up to a single scaling factor set by the coherence time of the system. We demonstrate the efficacy of these sequences in suppressing phase errors through measurements on a model qubit system, $^{9}$Be$^{+}$ ions in a Penning trap. Our combined theoretical and experimental studies show that in high-frequency-dominated noise environments this approach may suppress phase errors orders of magnitude more efficiently than comparable techniques can.