Noise-Resistant Quantum State Compression Readout

TL;DR

The paper introduces a compression readout method for quantum state measurement that reduces errors by compressing multi-qubit states into a single qubit, improving accuracy and calibration efficiency for near-term quantum devices.

Contribution

A novel quantum state readout technique that minimizes measurement errors and calibration complexity by using state compression into a single qubit for measurement.

Findings

Outperforms direct measurement in accuracy, especially as system size grows.

Requires only single-qubit calibration, reducing device calibration demands.

Diminishes correlated measurement errors, enhancing readout fidelity.

Abstract

Qubit measurement is generally the most error-prone operation that degrades the performance of near-term quantum devices, and the exponential decay of readout fidelity severely impedes the development of large-scale quantum information processing. Given these disadvantages, we present a quantum state readout method, named \textit{compression readout}, that naturally avoids large multi-qubit measurement errors by compressing the quantum state into a single qubit for measurement. Our method generally outperforms direct measurements in terms of accuracy, and the advantage grows with the system size. Moreover, because only one-qubit measurements are performed, our method requires solely a fine readout calibration on one qubit and is free of correlated measurement error, which drastically diminishes the demand for device calibration. These advantages suggest that our method can immediately boost the readout performance of near-term quantum devices and will greatly benefit the development of large-scale quantum computing.