Direct state measurements under state-preparation-and-measurement errors

TL;DR

This paper investigates the robustness of direct state measurement (DSM) in quantum tomography under state-preparation-and-measurement (SPAM) errors, proposing methods to improve accuracy in noisy quantum systems.

Contribution

It introduces a framework for analyzing DSM precision with SPAM errors and compares different configurations to enhance measurement reliability.

Findings

DSM accuracy decreases with SPAM errors

Certain configurations improve robustness against SPAM errors

The study offers a tool for SPAM errors tomography

Abstract

Direct state measurement (DSM) is a tomography method that allows for retrieving quantum states' wave functions directly. However, a shortcoming of current studies on the DSM is that it does not provide access to noisy quantum systems. Here, we attempt to fill the gap by investigating the DSM measurement precision that undergoes the state-preparation-and-measurement (SPAM) errors. We manipulate a quantum controlled measurement framework with various configurations and compare the efficiency between them. Under such SPAM errors, the state to be measured lightly deviates from the true state, and the measurement error in the postselection process results in less accurate in the tomography. Our study could provide a reliable tool for SPAM errors tomography and contribute to understanding and resolving an urgent demand for current quantum technologies.