Ben Bar | Searcharxiv

arXiv2025

Layered KIK quantum error mitigation for dynamic circuits

Quantum Error Mitigation is essential for enhancing the reliability of quantum computing experiments. The adaptive KIK error mitigation method has demonstrated significant advantages, including resilience to temporal noise drifts, applicability to non-Clifford gates, and guaranteed performance bounds. However, its reliance on global noise amplification introduces limitations, such as incompatibility with mid-circuit measurements and dynamic circuits, as well as small residual errors due to unaccounted high-order Magnus noise terms. In this work, we propose a layer-based noise amplification approach that overcomes these challenges without incurring additional overhead or experimental complexity. Since the Layered KIK method is inherently compatible with mid-circuit measurements, it enables seamless integration with quantum error correction codes. This synergy allows error correction to address dominant noise mechanisms, while the Layered KIK suppresses residual errors arising from leakage and correlated noise sources. Similarly, for reducing sampling costs, Layered KIK can be combined with complementary mitigation methods for providing drift resilience and broadening the range of addressable errors.

quant-ph↗

arXiv2024

Pseudo Twirling Mitigation of Coherent Errors in non-Clifford Gates

The conventional circuit paradigm, utilizing a limited number of gates to construct arbitrary quantum circuits, is hindered by significant noise overhead. For instance, the standard gate paradigm employs two CNOT gates for the partial CPhase rotation in the quantum Fourier transform, even when the rotation angle is very small. In contrast, some quantum computer platforms can directly implement such operations using their native interaction, resulting in considerably shorter and less noisy implementations for small rotation angles. Unfortunately, coherent errors stemming from qubit crosstalk and calibration imperfections render these implementations impractical. In Clifford gates such as the CNOT, these errors can be addressed through Pauli twirling (also known as randomized compiling). However, this technique is not applicable to the non-Clifford native implementations described above. The present work introduces, analyzes, and experimentally demonstrates a technique called `Pseudo Twirling' to address coherent errors in general gates and circuits. Additionally, we experimentally showcase that integrating pseudo twirling with a quantum error mitigation method called `Adaptive KIK' enables the simultaneous mitigation of both noise and coherent errors in non-Clifford gates. Due to its unique features pseudo twirling could become a valuable asset in enhancing the capabilities of both present and future NISQ devices.

quant-ph↗