Breaking the weak Heisenberg limit

TL;DR

This paper demonstrates that the weak Heisenberg limit can be surpassed under certain conditions, challenging previous assumptions about fundamental measurement limits.

Contribution

It introduces a simple example showing the weak Heisenberg limit can be beaten with improved prior information and no bias.

Findings

Weak Heisenberg limit can be surpassed

Prior information can be improved without bias

Simple example illustrating the violation

Abstract

We provide a very simple case showing that the weak form of the Heisenberg limit can be beaten while the prior information is improved without bias.