Skip to main content


Figure 2 | EPJ Quantum Technology

Figure 2

From: Nearly optimal measurement schemes in a noisy Mach-Zehnder interferometer with coherent and squeezed vacuum

Figure 2

Log plot of phase variance for various detection schemes for a coherent state and squeezed vacuum into an MZI, as a function of the unknown phase difference ϕ . Loss parameters have been set to \(L=20\%\). Input state parameters for each respective state are set to \(|\alpha|^{2}=500\) and \(r=1\). SNL and QCRB are also plotted with the same loss parameters. Note that a homodyne measurement nearly, but not exactly, reaches the QCRB as shown by the inset.

Back to article page