Error-Mitigated Digital Quantum Simulation.

Area of Science:

• Quantum computing
• Quantum error correction

Background:

• Variational algorithms offer potential for simulating complex problems on near-future quantum hardware.
• Hardware errors currently limit the practical application and accuracy of these quantum algorithms.
• Efficient error mitigation strategies are essential for realizing the potential of noisy intermediate-scale quantum (NISQ) devices.

Purpose of the Study:

• To introduce a novel stabilizerlike method for detecting errors in quantum computations.
• To assess the effectiveness of this method in mitigating depolarizing errors on near-term quantum hardware.
• To evaluate the method's performance under various noise models and in conjunction with existing techniques.

Main Methods:

• Development of a stabilizerlike error detection protocol.
• Simulations of quantum algorithms incorporating the proposed error detection method.
• Analysis of error detection efficiency for depolarizing errors (60%-80%).
• Assessment of performance under stochastic and correlated noise conditions.

Main Results:

• The proposed method can detect a significant portion (60%-80%) of depolarizing errors.
• The technique is compatible with the constraints of near-term quantum hardware.
• Simulations demonstrate substantial improvements in calculation accuracy when using the method, particularly with combined noise.
• The approach shows synergistic benefits when integrated with established error mitigation strategies.

Conclusions:

• The developed stabilizerlike method offers a practical approach to mitigate errors in variational quantum algorithms.
• This technique enhances the reliability of quantum simulations on current and upcoming quantum hardware.
• The error detection strategy is robust against different noise types and complements existing mitigation approaches, paving the way for more accurate quantum computations.