Protocol for Purifying Noisy Preparation and Measurements of Qubits

Abstract

Noise affecting qubit preparation and measurements accounts for a significant fraction of errors in quantum information processing. This is especially critical in tasks like variational quantum algorithms, quantum error correction, and entanglement distribution through repeaters. In this work, we present a protocol to purify noisy SPAM, effectively suppressing these errors to an arbitrarily low level. For instance, in a realistic scenario where qubits contain error rates around $0.05$ in both preparation and measurement, the protocol can suppress error rates up to $10^{-3}$ with two ancillas and $10^{-6}$ with four ancillas. We show how to distill error-free SPAM by repeating noisy SPAMs. The protocol is also feasible with superconducting qubits. We envisage that our results can be used to realize quantum information tasks in computing and communication with negligible SPAM errors.

arXiv comment15 pages, 7 figures

References in corpus (18)

• Quantum entanglement
• Surface codes: Towards practical large-scale quantum computation
• Purification of Noisy Entanglement and Faithful Teleportation via Noisy Channels
• Noisy intermediate-scale quantum (NISQ) algorithms
• Superconducting Qubits: Current State of Play
• The Variational Quantum Eigensolver: a review of methods and best practices
• Quantum repeaters based on entanglement purification
• Quantum error correction below the surface code threshold
• Quantum Error Mitigation
• Practical Quantum Error Mitigation for Near-Future Applications
• High-threshold and low-overhead fault-tolerant quantum memory
• A tunable coupling scheme for implementing high-fidelity two-qubit gates
• Tunable Coupling Architecture for Fixed-frequency Transmons
• Entanglement-Enhanced Quantum Metrology in Colored Noise by Quantum Zeno Effect
• Quantum cryptography on noisy channels: quantum versus classical key-agreement protocols
• Universal Sampling Lower Bounds for Quantum Error Mitigation
• Purification of noisy quantum measurements
• Purification of Noisy Measurements and Faithful Distillation of Entanglement