Correspondence: Enhancing a phase measurement by sequentially probing a solid-state system
Paul A. Knott, William J. Munro, Jacob Dunningham · Nature Communications · 2016
In a recent paper, Liu et al . 1 claim to perform the first room temperature entanglement-enhanced phase measurement in a solid-state system. We argue here that this claim is incorrect: their measurement is not enhanced because of the entanglement in their system, instead the enhancement comes from the fact that the phase shift is applied twice to their state.