QuTracer: Mitigating Quantum Gate and Measurement Errors by Tracing Subsets of Qubits

TL;DR

QuTracer is a novel quantum error mitigation framework that traces subsets of qubits to reduce gate and measurement errors, improving the fidelity of quantum computations on NISQ devices.

Contribution

It introduces the QuTracer framework with QSPC technique, enabling effective mitigation of both gate and measurement errors across various quantum algorithms.

Findings

Significantly outperforms state-of-the-art error mitigation methods.

Demonstrates scalability through noisy simulations and real device experiments.

Effective in improving output fidelity for multiple quantum algorithms.

Abstract

Quantum error mitigation plays a crucial role in the current noisy-intermediate-scale-quantum (NISQ) era. As we advance towards achieving a practical quantum advantage in the near term, error mitigation emerges as an indispensable component. One notable prior work, Jigsaw, demonstrates that measurement crosstalk errors can be effectively mitigated by measuring subsets of qubits. Jigsaw operates by running multiple copies of the original circuit, each time measuring only a subset of qubits. The localized distributions yielded from measurement subsetting suffer from less crosstalk and are then used to update the global distribution, thereby achieving improved output fidelity. Inspired by the idea of measurement subsetting, we propose QuTracer, a framework designed to mitigate both gate and measurement errors in subsets of qubits by tracing the states of qubit subsets throughout the computational process. In order to achieve this goal, we introduce a technique, qubit subsetting Pauli checks (QSPC), which utilizes circuit cutting and Pauli Check Sandwiching (PCS) to trace the qubit subsets distribution to mitigate errors. The QuTracer framework can be applied to various algorithms including, but not limited to, VQE, QAOA, quantum arithmetic circuits, QPE, and Hamiltonian simulations. In our experiments, we perform both noisy simulations and real device experiments to demonstrate that QuTracer is scalable and significantly outperforms the state-of-the-art approaches.