Quantum control for high-fidelity multi-qubit gates

TL;DR

This paper presents a quantum control method that achieves faster, high-fidelity multi-qubit gates, crucial for quantum error correction, by framing the problem as a Hamiltonian feasibility task and applying global optimization.

Contribution

It introduces a novel approach to quantum optimal control for multi-qubit gates, enabling faster and higher fidelity gates than previous methods.

Findings

Achieved >99.99% fidelity for three-qubit gates

Enabled control of four-qubit gates with high fidelity

Demonstrated faster gate implementation than prior techniques

Abstract

Quantum control for error correction is critical for the practical use of quantum computers. We address quantum optimal control for single-shot multi-qubit gates by framing as a feasibility problem for the Hamiltonian model and then solving with standard global-optimization software. Our approach yields faster high-fidelity ($>$99.99\%) single-shot three-qubit-gate control than obtained previously, and our method has enabled us to solve the quantum-control problem for a fast high-fidelity four-qubit gate.