Quantum computers hold immense potential for revolutionizing information processing, but errors in quantum operations present a significant challenge. To overcome this hurdle, it is crucial to achieve low error rates in entangling quantum operations. A recent breakthrough in neutral-atom arrays, a promising quantum computing platform, has shown the ability to perform two-qubit entangling gates with 99.5% fidelity on up to 60 atoms in parallel, surpassing the threshold for error correction. This achievement paves the way for large-scale implementation of quantum algorithms, error-corrected circuits, and digital simulations.
Understanding the Significance of Low Error Rates
Low error rates are essential for efficient quantum error correction and to unlock the true computational capabilities of quantum devices. Quantum error-correcting thresholds require two-qubit-gate error rates below 1% or fidelities above 99%. Maintaining such low error rates, along with highly parallel control and a high degree of connectivity, is crucial for scaling quantum computers to larger sizes.
Neutral-Atom Arrays: A Promising Quantum Computing Platform
Arrays of neutral atoms have emerged as a promising platform for quantum processing. These arrays offer coherent control over hundreds of qubits and feature a flexible, dynamically reconfigurable architecture. One of the key advantages of this platform is the ability to perform entangling operations between neutral-atom qubits with arbitrary connectivity and in a highly parallel manner. This unique capability enables both large-scale digital simulations and computation with error-corrected qubits.
Achieving High-Fidelity Entangling Gates on Neutral-Atom Quantum Computers
Until recently, achieving high-fidelity entangling operations on larger systems has been a challenge. State-of-the-art platforms had demonstrated fidelities around 97.5%. However, the recent breakthrough in neutral-atom arrays has closed this gap by realizing two-qubit controlled phase (CZ) gates with 99.5% fidelity on up to 60 neutral-atom qubits in parallel. This achievement brings neutral-atom quantum computers on par with other state-of-the-art platforms.
To achieve this high fidelity, a family of optimal gate schemes based on the Rydberg-blockade mechanism was employed. These schemes are robust to experimental imperfections and spontaneous scattering, which were previously dominant error sources. Additionally, several experimental tools were implemented to overcome other error sources such as atomic temperature effects, miscalibrations, and experimental imperfections.
The Path Ahead: Parallel, High-Fidelity Three-Qubit Entangling Gates
The breakthrough in achieving high-fidelity two-qubit entangling gates on neutral-atom quantum computers has opened up new possibilities for larger-scale quantum operations. The techniques developed can be generalized to entangling operations involving a higher number of qubits. This opens the door to experimentally realizing parallel, high-fidelity, three-qubit entangling gates.
Frequently Asked Questions (FAQ)
Q: Why are low error rates important in quantum computing?
A: Low error rates are crucial for efficient quantum error correction and unlocking the full computational capabilities of quantum devices.
Q: How does neutral-atom quantum computing differ from other platforms?
A: Neutral-atom arrays offer coherent control over hundreds of qubits and feature a flexible, dynamically reconfigurable architecture. They enable entangling operations with arbitrary connectivity and highly parallel processing.
Q: What is the significance of achieving high-fidelity entangling gates on neutral-atom quantum computers?
A: High-fidelity entangling gates enable large-scale implementation of quantum algorithms, error-corrected circuits, and digital simulations. They bring neutral-atom quantum computers on par with other state-of-the-art platforms.
Q: What are the next steps in advancing neutral-atom quantum computing?
A: The techniques developed for high-fidelity two-qubit gates can be extended to realize parallel, high-fidelity, three-qubit entangling gates. This opens up new possibilities for larger-scale quantum operations.
– [Original Article](https://www.nature.com/articles/s41586-021-03670-x)