Mechanically induced correlated errors on superconducting qubits with relaxation times exceeding 0.4 ms

Area of Science:

• Quantum computing
• Superconducting circuits
• Quantum error correction

Background:

• Superconducting qubits are leading candidates for fault-tolerant quantum computing.
• Understanding qubit loss mechanisms is crucial for advancing quantum technologies.
• Minimizing correlated errors between qubits is essential for quantum error correction.

Purpose of the Study:

• Investigate the dominant error mechanism in long-lived superconducting transmon qubits.
• Identify the source of fluctuating qubit lifetimes and correlated errors.
• Provide insights into error mitigation strategies for fault-tolerant quantum computing.

Main Methods:

• Realization of long-lived superconducting transmon qubits with fluctuating lifetimes.
• Development of novel time-resolved error measurements.
• Synchronization of measurements with pulse tube cooler operation in a dilution refrigerator.

Main Results:

• Achieved qubit lifetimes averaging 0.2 ms, exceeding 0.4 ms (quality factors > 5 and 10 million).
• Identified mechanical vibrations from pulse tube coolers as the cause of correlated bit-flip errors.
• Demonstrated that vibrations induce non-equilibrium dynamics in highly coherent qubits.

Conclusions:

• Mechanical vibrations are a significant source of correlated errors in superconducting qubits.
• Decoupling qubits from mechanical environments is a promising error-mitigation strategy.
• Findings advance the understanding of qubit error mechanisms for fault-tolerant quantum computing.