Imprecision plateaus in quantum steering

TL;DR

This paper introduces the concept of imprecision plateaus in quantum steering, showing that certain steering inequalities remain valid despite measurement imprecision, thus relaxing ideal measurement assumptions without losing detection power.

Contribution

It presents the first analysis of imprecision plateaus in quantum steering, providing criteria for their existence and demonstrating their practical applications in robust quantum tests.

Findings

Steering inequalities unaffected by measurement imprecision up to a threshold

Imprecision plateaus enable robust quantum steering tests

Applications in noise- and loss-robust quantum protocols

Abstract

We study tests of quantum steering in which the trusted party does not have perfect control of their measurements. We report on steering inequalities that remain unaffected when introducing up to a threshold magnitude of measurement imprecision. This phenomenon, which we call an imprecision plateau, thus permits a departure from the standard assumption of idealised measurements without any incuring cost to the detection power of steering experiments. We provide an explanation for why imprecision plateaus are possible, a simple criterion for their existence and tools for analysing their properties. We also demonstrate that these plateaus have natural applications when the assumption of perfect measurements is relaxed: they allow for maintaining both the noise- and loss-robustness of standard steering tests and the performance rate of idealised one-sided device-independent random number generators.