Blind calibration of a quantum computer

TL;DR

This paper introduces a blind calibration protocol for quantum computers that accurately corrects measurement errors using a single experiment, without prior knowledge of state preparation, demonstrated on a trapped-ion system.

Contribution

It presents a novel blind calibration method that simultaneously estimates multiple measurement error mechanisms from simple tomographic data.

Findings

Calibration parameters match directly measured values.

Method improves measurement accuracy in quantum systems.

Single-experiment calibration reduces complexity.

Abstract

The calibration of quantum measurements is limited by the ability to accurately prepare quantum states under unknown device errors. We develop an accurate calibration protocol for the measurement apparatus of a quantum computer that is `blind' to the state preparation. Blind calibration quantifies and corrects measurement errors from simple tomographic data on a noisy quantum state. Importantly, it calibrates multiple error mechanisms in a single experiment, eliminating the need for bespoke, separate calibration experiments. Using a trapped-ion quantum computer, we systematically demonstrate the accuracy of the method. We use blind calibration to estimate the native calibration parameters of the experimental system. The recovered calibrations are consistent with directly measured values and perform similarly in predicting the state properties.