Dynamically corrected gates for an exchange-only qubit

TL;DR

This paper introduces analytical composite pulse sequences for exchange-only qubits that perform dynamical decoupling and arbitrary rotations while correcting logical and leakage errors under realistic experimental constraints.

Contribution

It presents new pulse sequences that simultaneously correct for multiple noise sources and errors in exchange-only qubits, advancing quantum control techniques.

Findings

Sequences effectively correct nuclear and charge noise.

Sequences respect experimental constraints like nonnegative couplings.

Enhanced qubit coherence and control demonstrated.

Abstract

We provide analytical composite pulse sequences that perform dynamical decoupling concurrently with arbitrary rotations for a qubit coded in the spin state of a triple quantum dot. The sequences are designed to respect realistic experimental constraints such as strictly nonnegative couplings. Logical errors and leakage errors are simultaneously corrected. A short pulse sequence is presented to compensate nuclear noise and a longer sequence is presented to simultaneously compensate nuclear and charge noise. The capability developed in this work provides a clear prescription for combatting the relevant sources of noise that currently hinder exchange-only qubit experiments.