Encoding a magic state with beyond break-even fidelity

Area of Science:

• Quantum Computing
• Quantum Error Correction

Background:

• Quantum computers require error-correcting codes to perform logic gates and protect information from noise.
• Magic states are essential resources for completing universal sets of logic gates in quantum computation.
• High-fidelity magic state preparation is critical for minimizing noise in quantum algorithms.

Purpose of the Study:

• To propose and implement a novel scheme for preparing magic states using quantum error correction on a superconducting qubit array.
• To demonstrate that error correction can enhance the quality of logic gates produced by noisy qubits.
• To showcase the utility of adaptive circuits in increasing magic state yield for quantum error correction.

Main Methods:

• Implementation of a quantum error correction scheme on a superconducting qubit array.
• Preparation of magic states utilizing the proposed error correction technique.
• Application of adaptive circuits with mid-circuit measurements to optimize magic state production.

Main Results:

• The implemented scheme successfully produced higher-fidelity magic states compared to those prepared using individual qubits.
• The use of error correction demonstrated the principle of improving logic gate quality with noisy qubits.
• Adaptive circuits were shown to increase the yield of magic states, a key capability for error correction subroutines.

Conclusions:

• The developed scheme provides a method for generating high-fidelity magic states essential for fault-tolerant quantum computing.
• This work validates the fundamental principle that quantum error correction can improve the performance of noisy qubits.
• The prototype's ability to reduce the physical qubit overhead for magic state production is significant for future large-scale quantum computing architectures.